The hidden hues of colour mixing (video)

by Will Kemp

in acrylic painting,colour theory

Why can’t I mix the right colour?

Imagine a time of poster paints and sugar paper. Of bright colours, chubbie crayons, green grass and blue skies. These were perfect painting days apart from one thing I almost forgot to mention….brown sludge.

Lots and lots of brown.

Your teachers told you ‘mix yellow and blue to make green’, red and blue to make purple.

You listened, but the problem was still there.. you created brown sludge.

What were you doing wrong?

Nothing, you were just given the wrong paints…

The hidden secret in paints

The way paint looks when it comes straight out of the tube is usually very different to how it reacts when you start painting with it. This is especially true with darker colours, the lighter colours such as yellow often behave much as you would expect, hence why a yellow sun always worked at school.

So the primary colours red, blue and yellow alone are not the whole story. Small amounts of other colours are hidden within each pigment – this gives each colour a colour bias.

Colour theory is misleading

The colour mixing wheel is a great tool, it is handy to have one in your studio for quick reference.

Remembering all the complementary colours when you are starting painting can be tricky.

However, if you take the theory at face value you are in for hours of frustration when trying to mix the colour you want.

What is colour bias?

Every single colour has a bias towards another colour.

A blue pigment will have either a red bias or a green bias in comparison to another blue pigment.

Colour ‘theory’ states that you can mix all 3 secondary colours with the 3 primaries,
However, this will only work if a ‘pure’ primary colour is used.

With paint pigments you can’t find a ‘pure’ red, for example, that will make both a good orange (when mixed with yellow) and a good purple (when mixed with blue).

This is because the red will have a bias towards either orange or purple due to the chemical impurities found within every pigment. (see What are my Acrylic paints made from?)

So a red that has an orange bias (Cadmium Red) will mix a bright orange, but will not mix a bright purple.

Blue & Yellow don’t make Green

You mixed the correct colours, a blue and a yellow, but the finished colour is a dull, murky green. Not the vibrant colour you had envisaged.

So what do you do?

Add more yellow? It gets a bit lighter but is still wrong, what about more blue? no, now it’s too dark…what it needs is brightening up, so you reach for the white paint, only to find this doesn’t work either your left now with a grey looking green.

Disheartened, you make another trip to the art shop to buy a pre-mixed bright green.

Why didn’t the colours mix to the colour I wanted?

How to mix a bright green

The greenest or cleanest green is made by using a green shade blue and a green shade yellow. (check out the video above at 1 min 12 sec)

  • Ultramarine blue has a red (warm) bias so would be the wrong choice for vibrant green.
  • Phthalo blue has a green (cool) bias so this would be a good choice for a bright green.
  • Cadmium Yellow has a red (warm) bias so would be the wrong choice for vibrant green.
  • Hansa yellow has a green (cool) bias so this would be a good choice for a bright green.

Option 1:      Ultramarine blue  + Cadmium Yellow light = muted green
Colour Bias      (purple-blue)       + (orange-yellow)

Option 2:              Phthalo Blue + Hansa Yellow medium = bright green
Colour Bias               (green-blue) +  (green yellow)

If we look at the colour bias on Option 1 we are essentially mixing 2 complementary colours blue and orange together.

Complimentary colours are those that lie opposite each other on the colour wheel and will mute each other out, making it impossible to make a bright clear colour.

Option 3: Cerulean blue + Hansa yellow = very bright green

So in Option 3 we have a yellow that has a large amount of yellow and small amount of green. Mixed with a blue such as Cerulean blue, which has a large amount of blue and a small amount of green resulting in a very bright green.

Hansa yellow

  • large amount of yellow
  • Small amount of green
  • Very Tiny amount of orange

Cerulean blue

  • Large amount of blue
  • Small amount of green
  • Very tiny amount of purple

The secret to effective colour mixing is understanding the different pigment qualities of paints so you can match the colour you want every time.

For a more intensive look at colour bias I recommend you have a look at Blue and Yellow Don’t Make Green by Micheal Wilcox.

It gets a tad scientific and can be a bit overwhelming to start with but if you paint with watercolours has a huge selection of samples of different colour mixtures you can make.

You might also like:
How your hairdresser can teach you to mix colour
Colour mixing basics with Acrylic paint

{ 44 comments… read them below or add one }

Alison Stafford September 16, 2011

Love this demo Will – it all makes so much sense when you see it happening before you. Still can’t mix a decent bright pink though. What red would you use as a base? I have been using Alizarin Crimson :)


Will Kemp September 16, 2011

Hi Ali,
Glad it starts to make sense. If you are using Alizarin Crimson it will not be a super bright pink, but Alizarin Crimson Permanent mixed with pink (Winsor & Newton Artists’ Acrylic) will go alot brighter.


Marian rowling October 18, 2011

How can you get an idea of colour bias without actually buying lots of paint and mixing them Will. I am just beginning with oils and trying to work out a simple, affordable palette of colours to buy.


Will Kemp October 18, 2011

Hi Marian,
It can be hard to judge how much a colour will be bias without actually painting with it.
The colours I recommend in ‘How to choose a basic colour palette for acrylic painting” have been chosen specifically so they will work as well with oils as acrylics. You can get all the colours from the winsor & newton artist range and as there are 5 tubes recommended as a starter palette with a mix of series numbers, it works out affordable for high quality. You should be able to mix 80% colour range with these pigments .
Burnt umber, ultramarine blue, cadmium yellow light, permanent alizarin crimson and titanium white.
I also recommend an extended palette in the article.
Good luck experimenting.


Marian rowling October 20, 2011

Many thanks Will that’s a big help.


Will Kemp October 20, 2011

Your welcome Marian, glad to be of help,


Linda October 19, 2011

Hi Will
what would you use for a Caribbean turquoise ocean? i feel like an injection of turquoise with winter coming on and the nearest I will get to the ocean will be mixing up the colour myself? Thanks !


Will Kemp October 19, 2011

Hi Linda,
The brightest turquoise will be mix of a yellow/ green and a blue/ green.
In Winsor and Newton that will be Winsor yellow and Winsor Blue GS, the GS stands for green shade.
In other brands these are known as Lemon yellow or Hansa yellow and Phthalo blue GS.
However I use Cadmium yellow light and Winsor blue as this has a better coverage than the Lemon yellow which is a more transparent paint.
And although Cadmium yellow light has a warmer bias, the Winsor blue is so green – it will still give you a great turquoise.


Jay Shah February 2, 2012

Mr. Kemp,

Is there a text or website you could recommend that has information on how to mix one’s own paints – what materials are required and methodology?




Will Kemp February 3, 2012

Hi Jay,

Why don’t you have a look at to read further on this interesting subject.
Tony Johansen has an easy guide for artists and is very informative. He also has a good bibliography for further reading.



Jay Shah February 6, 2012

Thanks for the info…it is an excellent site. I am really enjoying painting in Acrylic and feel less of a beginner as each day passes. Much of this has been due to your website, your advice and information. Your willingness to freely share information and tips that many others charge for is appreciated. Thank you….truly.


Will Kemp February 6, 2012

Hey Jay,
Very kind of you to say so, pleased to be of help on your painting journey.


John Moulding-Dayas February 29, 2012

Hi Will,
Just watching this whilst waiting for the ‘Beginners Drawing Course’ to get underway! Keep saying to myself ‘fascinating – I didn’t know that’!
Think I’ll be saying that for some time to come!
So looking forward to all of this!
John M-D


Will Kemp March 1, 2012

Hi John, Glad it’s being of help. Understanding the pigments and what you can or can’t mix with them is so key to understanding painting. See you on the drawing course soon!


Alston Edwards March 22, 2012

I’m not an artist but a student photographer can I asume that a colour bias is when one colour leans towards another colour like you said, or am I understanding it wrong.


Will Kemp March 23, 2012

Hi Alston, yes that’s right. Because pigments in paint are never 100% pure, as in they have trace elements of other colours in them, there will always be a colour bias. So a red will either make a bright purple and a dull orange or a dull purple and a bright orange. You can’t find a red that will make a very bright orange and very bright purple due to the trace elements of other colours.
Hope this helps clarify it,


Brian Sutherland May 23, 2012

Hi Will,
Just a note to say thanks for the insights. I have just started going through your free material and getting many aha moments. Keep up the great work.
Best wishes,


Will Kemp May 23, 2012

Hi Brian,
Thanks for the comment. Great to hear you have been having those ‘aha’ moments. Especially with colour mixing, you can get a breakthrough when it just all clicks.


Faith Ellis October 22, 2012

G’day from Australia Will,
I have just started exploring painting with a basic kit of Atelier acrylic paints and brushes inherited from my mother. I have been so frustrated because I keep producing muddy colours and failing to get the results I want. Your videos and articles about colour and brushes are providing me with vital basic information. You have become my #1 learning resource .. .thanks heaps.


Will Kemp October 22, 2012

Hi Faith,

So pleased to hear it, really pleased you’re finding the site helpful in your painting.




Hui Sun January 11, 2013

Hi, Will,

As a beginning acrylic painter, I find your website to be a treasure trove of critical and well-delivered information. Thank you so much for your teaching– it’s greatly appreciated!!

The question I have is about the relative warmness/coolness of ultramarine blue vs. pthalo blue. It seems that experienced painters all over the internet have sharply conflicting information about which is warmer, which is cooler. Ultramarine blue has more red in it than phthalo blue, so it seems warmer. However, ultramarine blue is also closer to the cool violet while pthalo blue has more yellow in it, so ultramarine blue seems cooler. When I mix pthalo blue with a warm red, I get a browny color (which I think is warm), and when I mix ultramarine blue with a warm red, I get a violet-y color (which I think is cool).

Is it just semantics? I can intuitively tell the temperature of reds and yellows when I’m looking at them, but my intuition fails me when I look at blues. I’m so confused! Help!

Thank you,
Hui Sun


Will Kemp January 17, 2013

Hi Hui Sun,

Thanks for getting in touch, great to hear you’re enjoying the website.

All colours vary depending on what other colours they are next to and what other colours you are comparing them to.

In general terms:
Ultramarine blue is a warm blue
Phthalo blue (Green shade) is a cool blue
Phthalo blue (Red shade) is a warmer shade than Phthalo blue (Green shade) but cooler than Ultramarine blue.

I use ‘in general terms’ as it is a guide, adding white to any pigment will reveal the colour bias of that colour, or the mix of colour.

As long as you understand the individual pigments, it can help guide you to mix the colours that you are trying to achieve, rather than worrying how to categorize them to absolute system.
For example, you could mix a cool violet, put it on your painting next to a blue and suddenly what you had identified on your palette as being cool, now appears to be warm, in comparison to the blue – so that is why it is a guide, rather than an absolute rule.

Hope this helps explain it,




Hui Sun January 25, 2013

Thanks so much for clarifying, Will. I’m finding that, as everything in life, nothing is strictly “either-or” — and that includes colors!


Will Kemp January 25, 2013

You’re welcome Hui,



maebel January 17, 2013

Hi Will,

thank you for sharing this site especially for beginners like me. I’ll recommend this site too to some of my friends here in the philippines.

more power and keep going,


Will Kemp January 17, 2013

Cheers Maebel, Thanks for spreading the word in the Philippines!



J February 9, 2013

This totally explains why I have only been able to paint only with a watercolour palette! I look forward to now using other media with science in mind.


Will Kemp February 9, 2013

Great to hear it J,



Mary February 12, 2013

Hello Will,
Could you reccomend a red and a blue that would have the correct bias’ to make a clean, bright purple? So far I have tried Ultramarine/Crimson Red Lake and Ultramarine/Vermillion, and both have come out looking like varying shades of gray mud.


Will Kemp February 13, 2013

Hi Mary,

A permanent alizarin crimson will allow you to mix some nice purples, and even brighter would be a Quincridone red.

Have a look at this video : How to mix a bright purple



diane February 25, 2013

A couple hours ago I just totally ruined a painting that I was really liking so far, because I went out and bought a new tube of blue, and new tube of red, thinking I could just make purple, like they told me in kindergarten right? I mean how hard can that be? I know what I did wrong now, and it was a terrifically painful lesson, but at least i know why the whole thing looks like a grey muddy mess. Thanks for helping me to clarify where I went so wrong. Great site here !


Will Kemp February 25, 2013

You’re welcome Diane, it can be a bit disheartening when you’re faced with grey, rather than a vibrant purple. You might be interested in thie video on mixing bright purples. Pleased the tutorial helped.



Steve Cardwell June 19, 2013

Hi Will,

Firstly, let me thank you for an incredible site. It’s great to have so much information available in one place.

I took life-drawing classes last year and had the opportunity to use acrylics for the very first time. With a lot of beginner’s luck I managed to have some half-decent results and so I carried on painting after the classes had finished. The problem I have now is that I have no understanding of materials or technique but I think your site will help me greatly.

Going forward I’m going to base my palette on your five-colour advice; how would I mix the bright green shown in the video if the palette only includes Ultramarine?

Many thanks


Will Kemp June 20, 2013

Hi Steve,

Nice to hear from you, pleased you’ve been finding the site helpful.

To mix the bright green you’ll need ‘Phthalo Blue Green shade.’

This is the vivid blue and will enable you to mix bright greens even with the Cadmium yellow light.

For the brightest possible green you’d need a cool yellow such as Hansa yellow light.

So you would have a blue with a green bias (Phthalo Blue Green shade) + a yellow with a green bias (hansa yellow light)

However, Phthalo blue has a very high tinting strength and Hansa yellow a very low tinting strength so it is harder to adjust the mixes if you’re just starting.

Hope this helps,



Steve Cardwell June 20, 2013

Thanks Will,

So I take it bright green is one of the colours that would fall out of the 90% possible with the five-colour palette? And why Michael Wilcox recommends the palette of six primaries.



Will Kemp June 20, 2013

Exactly, it’s in the 10%.

You could also add a red such as cadmiun red for painting opaque orange reds.

It all depends what the end result is you’re after, have a look at this article on choosing paints dependent on the results you’re after.



Steve Cardwell June 20, 2013

That’s what I thought.

I only discovered your site this week and have already ditched my 20 colour beginners set, replacing it with just the five. I’m going to work with these for a while until I’m comfortable with them and then slowly add just a few more for brights.

I think by the time the week is out I’ll have watched all your videos.

Thanks again.

Tom September 2, 2013

Hi Will! It would sure be great if the paint manufacturers would note the color bias on the label. It should be very easy for them to do. A nd it would save a lot of user frustration. Cheers!


Will Kemp September 3, 2013

Hi Tom, yes it would be handy to have an idea on the side of which way the colour would go when white is added. They don’t tend to label them with a bias as the bias can change depending on which two colours you are comparing.



Ingrid December 24, 2013

I just recently discovered your blog, and it is so. helpful! I went back in my previous work and saw that my paintings where I work with fewer colors are better. As soon as I add a color I tend to spend a lot of time saving it because i’m working with too much and can’t get the value from it.
Your explaination of the color bias is very usefull , I’ve had some problems with green and yellow, and completely stopped using them because I was tired of failing.

Could you do a post on white some time? I have more of a drawing-background and find that my paintings are many times better when I use only black (or one color, like with a pencil) on a white primed canvas and go gradually darker until finished. I get problems when I get too dark and want to lighten it, so I’ve figured titanium and zinc or mixed whites make an extra … bluh, layer that ruins the debth of my painting. Not sure if I’m explaining it well, but it keeps happening . I’ve recently discovered that using a primer instead of acrylic whites work better because it is closer to the primer color of the canvas which is the same I leave for highlights when I paint only with black.
here’s one in progress at a stage where I was happy with the white “behind” the black: . I learned by failing that adding a transparent layer of black after applying white helps, but it often creates too much of a distance, or still has this harsh , on-top-of-tone that I don’t want.

Sorry about the long explaination, I hope that was clear enough. Thank you for sharing your knowledge, and I hope you have some tips for me on the white!


Will Kemp December 30, 2013

Hi Ingrid,

Nice to hear from you, and so pleased you been finding the blog helpful in your work. When working with white its really a choice of opacity and subtle changes in the whiteness of the white.

Here’s an excerpt about white when used in Oil painting:

3 Different kinds of White

Flake white – This is a lovely white that brushes out nicely and has a nice flexibility in the paint film. It is also a quick drier compared with Titanium white, so is useful for under paintings. This makes it a great white for mixing subtle tones when working with a full palette for oil portraits as you can shift the colour, yet still work in semi opaque layers to develop the skin tones.

It has a semi-opaque finish and is the least white of the white. For finishing highlights, or a really bright white, Titanium white is a better choice.

Titanium white – I find this is the most opaque and bright white, it is a slower drier than Flake white and is very thick when it first comes out of the tube.

Pro tip: I often mix my Titanium white with OMS just to create a more flexible and free flowing consistency, I then keep a small blob of the pure white for adding the thickest, brightest highlights.

Zinc white – Another semi-opaque white used for mixing and subtle-tinting of colours, I personally don’t use this much in my paintings.

Lead based pigments:

The perception that “oil paints are hazardous” comes from the use of lead based pigments.

Until the beginning of the 20th Century, lead whites were the only opaque white pigments available, Zinc white was available but had more transparency and a tendency to dry slowly, so was hard to paint thicker, solid colour.

In the mid 1920′s non-toxic Titanium White was introduced and gave artists a non-toxic alternative. So historically, painters have been exposed to much higher levels of toxic pigments than modern day painters.

However, some artists continue to use lead white because of its interesting working properties. Lucien Freud loved it so much he bought it in bulk, fearful Cremnitz white was going out of production.

A note about Lead Whites

Flake White No. 1
Cremnitz White
Foundation White.
Lead white has been used traditionally by the Old Masters, and as such is often viewed in high regard. However due to the toxic nature of this paint it is often only available in tins and recently has had issues with health and safety.

They are fast drying and offer a high degree of flexibility and as a result they are often used for portrait work.

Specifically, Flake White No. 1 has a creamy consistency and handles really well.

Cremnitz White is ideal for achieving sculptural effects thanks to it unusual almost stringy consistency.

Foundation White is a traditional lead based white, ground in Linseed Oil which thanks to its fast drying rate, is ideal for priming.

Hope it helps,



Linda Jo February 3, 2014

I am a beginner (in acrylics, anyway) and am stressing over the question of artists quality paint (ie: artist versus student grade.) First, just because the description says ‘artists quality’, does that make it true (for example, Talen Amsterdam paints)? And second, can you mix different grades (ie: student and artist) and different brands
(ie: Talen and Golden)? Thanks in advance, Linda Jo


Will Kemp February 4, 2014

Hi Linda,

Yes you can mix artist quality and student grade. Many paint companies have a student and artist range, but artist quality can vary between brands, but most will be pretty good – Talen & Golden are both nice.

I always recommend starting with an artist quality titanium white as this will give you the most ‘bang for your buck’ you can then start with other student colours and expand when you feel you want to.

Hope this helps,



Will Kemp June 20, 2013

Perfect way to do it Steve, start with the fewest colours possible and then add brighter colours as your colour mixing skills improve.



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