Wheeeee the colour wheel!!

This is my basic go-to exercise to quickly check out a set of colours, or to see how a new colour can interact with some existing ones.

Taking off from the last post about my approach of primary colours being CMY over RYB, here I want to explore a bit more in depth how we can use this CMY colour wheel to explore the range of colours that a triad can produce, along with some thoughts about its limitations, and alternates to explore those limitations.

Skip the history and jump to the colour wheel if you so wish – here!

History of the colour wheel!

If you remember Newton’s prism experiment, he observed that white light is made up of a spectrum of the ROYGBIV which lay next to each other in succession.

He also observed that the two ends of the spectrum could merge quite seamlessly, and hence ‘wrapped’ the spectrum around to form the first colour wheel. Incidentally, he did not place hues on the colour wheel to represent primary or secondary or any such hierarchy of colour, but just placed the visible spectrum of light (with their ratios of visibility relative to one another) on a 360degree space.

Here is the Newton colour circle

Isaac Newton, Public domain, via Wikimedia Commons 

He used this to demonstrate additive mixing by spinning this as a disc- also called Newton’s colour disc. Spinning this disc with the visible spectrum, would imprint those colours on the eye in a rapid motion, mixing optically and produce…. (didja guess it?)- WHITE!

It really is a demonstration of additive colour mixing, but taking this idea to painting, with ‘primary’ colours on a wheel, that too placed geometrically at the places of 12, 4 and 8 on a clock, is purely a man-made invention.

So- does the colour wheel really represent the true be-all and end-all of colour theory?

Honestly- NO!  It is just one way envisioned by humankind to explain the intersection of colour properties and our vision and simplify things. But can it be helpful? I choose to think YES!

You can learn a bit about the wheel and use it as a shortcut to help you make quicker painting and paint mixing decisions.

While I debunk the RYB colour wheel and wax lyrical about the CMY one, keep in mind, this is simply what has worked with the available pigments we have in watercolour.

The colour wheel itself is limited by the following facts:

1. Human eye can see more variation in the yellow-orange section, and more pigments have been discovered/ invented in the same. So, it does look like an overwhelming part of the colour wheel focuses on those hues. – especially the RYB wheel.

2. There has been no rule really that only three colours should mix all other hues in the world. Who produced this arbitrary idea and called them ‘primaries’?

3. Taking CMY from the print world is also not the best path, since the CMYK printing standard evolved to produce maximum colour range in minimum inks, and was driven by budgetary constraints, not colour theory necessarily. I only use the CMY wheel as a better option than the RYB wheel. The prevalence of colours like ultramarine and vermillion in our history might account for those being seen as ‘primary’ colours, enforcing the RYB wheel idea.

4. Why 12 hues from 3 primaries? Why a clock-like equidistant spacing around a circle? Why not a colour triangle or square or any other shape? Once again, an arbitrary decision that has simply become the norm over time. The 12-step wheel doesn’t give us everything we need to resolve colour questions, representing all hues our vision perceives.

Here is a Wikipedia article for more on the history of the colour wheel!

Despite all these limitations, here is why it’s worth giving the colour wheel a study.

1. It gives one a starting point of understanding how some colours work and with some predictability.

2. A triad of colours (whatever three colours they be) allows for a painting with harmony since all colours appearing in the painting are mixed from the same initial three thus ‘gel well’ with each other.

3. It is the fastest way to see the basic mixes with a triad of colours than making an entire mixing grid. While a mixing grid can show you more hue possibilities, it does take an awfully long time while a colour wheel can get you somewhat there, quicker.

4. In watercolours specifically, it can help you achieve clear transparent and bright mixed hues than murky ones – especially as shown with this CMY wheel.

Take everything below with a grain, nay, a spoon of salt. But give it a read, it might help you!

CMY Colour Wheel

Here is a colour wheel, with the three primaries, the three secondaries and the six tertiaries.

Taking from the artists’ tradition from centuries ago, I have created a wheel with geometric divisions, only replacing ye’ ole’ RYB with CMY.

I have named the tertiaries quite roughly on what it looks like or is derived from. (Unlike a RYB wheel where the tertiaries are named based on the two primaries that it is composed of.)

Recalling my previous CMY colour wheel, the tertiaries have a massive range of hues beyond the typical six. Each colour being so intense, can yield such a range in just their dilutions. So, I’ve added here a freeform blend of the primaries to show the range that is possible.

The high intensity (or chroma or saturation) of those primaries is the reason, the secondaries are overall still bright and clear.

The maximum saturation of a colour is what comes straight out of a tube. as it gets increasingly mixed, the saturation can only reduce. despite that, the secondaries here are quite saturated.

A quick explanation of what we can learn from this particular colour wheel:

Additionally, the possible colours we can get from this combination are more hues in the yellow-red range like scarlet, vermillion, Indian yellow and more. More aqua and turquoise hues, and more variations in green. These are hinted at in the freeform blend (1st ring from centre after black).

The original three primaries have high saturation, and would need to understand how to mix them to create duller hues like browns, ochres, earthy colours etc.

We have tints and shades of these hues – mixed with black (outer ring) or lightened with water (2nd ring from centre). Read more about these in the note below.

Things we don’t see directly here are: Complementary colours. For now, they are simply the colours opposite one another on the wheel. More below.

Other common colour schemes we can derive from a colour wheel are- Analogous (colours next to each other), Split complimentary (one colour and the 2 colours on either side of its opposite), monochrome, all tints, and shades of one colour. These are useful for selecting a limited range of hues for creating a piece of art, or design.

A note on tints, shades, and complements:

Tints are the lightened (with water) version of the hues.

Why do we not mix with white? Well white watercolour is looked down upon by ‘pure watercolourists’ and tends to make the colours a bit opaque if mixed. Hence in most transparent media, the white often comes from the white of the painting surface, here- the watercolour paper.

In a few experiments, I found my whites becoming dull and not giving the results I wanted. So I have over time, stopped using white in mixes and reserve it only at the very end for highlights or recovering some lost lights. This is not to say you can’t use white, nor that I am a purist in watercolour! Go ahead, try your own experiments, and see what works for you!

Complementary colours

Complementary colours are those that complement each other. “How?” you ask?

When complementary colours are placed next to each other, they make each other look more intense than they would on their own. This is because they have maximum contrast with each other. This is called Visual Complement.

Complements also mix with each other to neutralise each other, i.e.- cancel out that vibrance and produce a neutral grey. (They complete each other by bring together all three primaries, hence complement). This is called Mixing complement.

Surprise surprise! Visual and mixing complements may not be the same! This is because the representation of the hues from the visible spectrum in physical paints are unpredictable and all have different properties based on their composition and cannot behave reliably like light could be expected to. You often find that though a pair of colours neutralise each other, they may not have the highest visual contrast with each other, aka not visual complements.

On the other hand, we also find that one colour can sometimes mix to grey with many other paints, which are all its mixing complements.  OOf! There is so much more to this it boggles my mind sometimes.

But at the simplest, we can take colours which lie across the wheel to at-least be mixing complements and try mixing them with each other.

So some complementary pairs from the above wheel are:

Cyan + Red – shown with a cyan coloured line

Magenta + Green – shown with the magenta coloured line

Yellow with Purple – shown with the yellow coloured line

To satisfy the condition of being ‘mixing complements’ the two colours of a pair when mixed, should yield a neutral grey.

That makes sense because: Each secondary is the combination of the 2 primaries next to it (not including the primary on the opposite side of the wheel).

To make that simple,

Cyan + Red
= Cyan + (Yellow + Magenta)
= C + M + Y = Mixed Black

In this way, each pair of complementaries are the combination of the 3 primaries.

But as I try to mix these to show them in action, we hit a stumbling block.

It is difficult to get the same dark black as when I directly mix C+M+Y.

I can try adding more of the primaries to reach black, but I end up with varying neutralized hues which are biased towards one of the 3 primaries. Why does this happen?

There are two reasons for that:

A secondary can be considered a 1:1 mix of 2 primaries.
So if we mix 1 part yellow with 1 part magenta, we get 2 parts Red. ie: 1 Yellow + 1 Magenta = 2 Red
Thus 1 red = 1/2 Yellow + 1/2 Magenta
But when we mix complements, we also mix them in a 1:1 ratio. This leads to an imbalance of the 3 primaries in the mix. An Illustration of that below.

Taking our above example of Cyan + Red,
Cyan + Red
= 1 Cyan + 1 Red
= 1 Cyan + (1/2 Yellow + 1/2 Magenta)

Thus it reaches a hue not-quite-black, which end up in the world of browns, olives, dull purples, deep blues and so on. These are our earthy hues that were missing in the wheel and using complements can help us obtain them.

But then are these truly ‘complements’ when they don’t make a grey? This goes back to the actual secondary and tertiary colours created here.

The primary hues are intensely pigmented. Thus the ratios of paints can be difficult to match while mixing the secondaries and tertiaries. A hue can swing wildly from a deep Indian yellow to a dark red in an instant. I could easily find more hues in between these painted swatches and call those secondaries or tertiaries as well.

While mixing the complementary, I create golden brown to an olive green with the same 2 hues. This is just because of the strength of the original primaries.

So that shows me some of the problems with my CMY colour wheel.

What can we take away though? We observe that colours opposite each other on the wheel do neutralise each other, even if not to a perfect grey. So, if we wanted to ‘tone down’ or reduce the saturation of any colour, we can do so by adding it’s complement.

For eg: the greens produced in this wheel are very bright, but also very unnatural to represent any natural foliage. They range from the intense turquoise greens to the bright yellow almost-neon greens. These can be neutralised by adding any of the opposite colours, such as a touch of orange-red-magenta hues. That will neutralise and make them more natural looking.

I will share some mixes with these CMY primaries in the follow-up to this post.

Edit:

This post is part 3 of a 5-part series on colour theory and the basics of the colour wheel. The others in the series are linked below.

1 Primary Colours?

2. Colour Vocabulary – Hue, Value and Saturation

3. The CMY Colour Wheel (this one!)

4. Colour Temperature

5. Expanding the CMY colour wheel