What are warm and cool colours and why do we need to know which is which?
Some colours are easy to tell if they are warm or cool and others not so much. The problem is we don't all see colours the same.
Whether a colour is warm or cool is also relevant to what colours are around it.
In general, we can say that yellow, orange and red are warm colours and green, purple and blue are cool.
In painting these colours are broken down again and you can get warm yellows and cool yellows. A green-yellow is a cool yellow, what I would call a lemon yellow. An orange-yellow is a warm yellow. Warm reds are orange reds and blue reds are cool.
Most colours are pretty easy to tell the difference. But then there is blue!
Blue can be a tricky one and there seems to be a lot of conflicting opinions on if ultramarine blue is warm or cool.
Technically Ultramarine blue is closer to purple on the colour wheel and therefore should be a cool colour.
Pthalo Blue is closer to green and therefore a warm colour
So why the confusion? Maybe because ultramarine has red in it to make it more purple and we think of red as a warm colour. Or if you are like me, when I look at ultramarine blue it feels like a warm blue to me. Although Pthalo green is a cool green compared to some other greens. Pthalo blue is a warm Blue. So I can see how this can be confusing. So if you can't figure out if a colour is warm or cool then forget about the temperature of the colour and just think about the colour bias.
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What is colour Bais and why is it important?
Colour bais is which way on the colour wheel does that colour lean towards. Does that blue lean towards the red side of the colour wheel or the yellow?
Improve your colour mixing skills by knowing this one thing
Knowing this is important as it will affect your colour mixing skills.
For instance, if you want to make a clear bright purple. Knowing the colour bais of your reds and blues will help you create that colour. You will want a red bias blue rather than a yellow bias blue because if you put yellow in your purple mix it will dull that colour.
If you are trying to make a bright green or a dull green you will know how.
You will be able to successfully choose which colours to mix together to get the colour you want. So the temperature of the colours is not the important thing here but knowing your colour bais.
Knowing the colour bais of your paints is the key to frustration-free colour mixing.
The other reason you want to know what the colour bais is for you blue paint is when you want to create a sense of depth in your painting.
We think that warm colours will come forward and cool colours will recede.
For example, when I paint poppy flowers I will do the background flowers in a red that has a blue bias and as the flowers come forward I would use brighter more intense red-oranges (Warm Reds) until I get to the foreground flowers which would be fire-engine red or bright orange-red with yellow or orange highlights.
So what to do with blues?
Well if we went by the colour chart and said ultramarine was a cool colour then when I was painting a sky I would paint ultramarine blue in the distance and move to warmer or more yellow based blues at the top of the painting which would be closer to me as the viewer. ONLY I DON"T DO THIS.
In our New Zealand sky, this is the wrong way around as I see the colours in the sky.
Two paintings showing how I do the sky with ultramarine at the top and Pthalo blue at the bottom.
Ultramarine blue is definitely right above my head and on a sunny day it fades out to the Pthalo blue colour.
You can see why I get confused about blue.
Apparently, everyone sees colour slightly differently. Is it a scientific fact but also I know this from my childhood, as my mum and I could never agree on what a colour was.
Look at this colour study below or better yet make your own as you will be able to see better that way.
Using Pthalo blue (green-blue) and Ultramarine blue (red-blue) paint a circle of each colour and then do a circle around it of the other blue. Now study these cirles and see which colour blue looks like it is coming forward to you? There is no right or wrong answer here it is just how you see the colour. You may see it differently from me.
I see ultramarine as coming forward which is the red bais blue, which is the opposite to what the colour chart tells me I should.
You really need to do this exercise for yourself as colours on the screen are never right especially Pthalo blue
What is important is that once I have made the decision, that I am consistent. Since I see the red-blue coming forward I want to use the green-blues in my backgrounds or where I want the blue to feel further away. As long as I am consistent within a painting I can do whichever way around I want. So as long as you know which blues come forward to you and which recede then stick to that on a painting.
Hopefully, this blog will help clear up some of the confusion out there and help you to understand how you see colour and how to mix it.
Here are some more blog posts you might find helpful
Here is a video I did on blue and even some makeup tips that apply to painting as well.
Here is my youtube channel if you would like to see more videos on art or makeup.
What would you like to know more about with your painting? Comment below and I will do my best to make a blog on it for you.