A bit of colour theoryThere are two ways to look at colour: the additive and subtractive approaches. The additive approach is sometimes referred to as RGB (red-green-blue) because when you add red, green and blue lights together, you end up with white light. Additionally, when you add two lights together, they make a third, brighter light. What’s most notable is that the three “secondary” colours are brighter than the primary red, blue, and green because they reflect more light and absorb less.
Which Approach to Use
With objects like clothes, food, and living room walls, using a subtractive approach makes the most sense because the colours are made of pigment (like paint or ink) rather than light.
All the colour watches I have painted and posted here are made using exclusively cyan, magenta, and yellow paints. The blues you see in my colour wheels here are made by mixing only magenta and cyan.
The New Colour WheelWe've established that cyan, magenta, and yellow are primary colours, and when you mix two primary colours you get secondary colours: red, blue, and green. But what about orange? And more importantly, what about purple? It turns out these two are tertiary colours, those transitions between primary and secondary colours.
Red = magenta + yellow
Blue = magenta + cyan
Red + Blue = magenta + cyan + yellow
This makes for a muddy mix.
Most of the colours we encounter in daily life are not quite so bright as the swatches I've painted here. So where on the colour wheel do they fit? More on that next time.