The colour relationships section continues to talk about another kind of opposition of colours on the colour circle – those that appear cold (blue-green) and those that appear warm (orange-red). These are entirely perceptual – and down to obvious associations such as the blue of a body of water and the orange glow of fire.
Looking at recent photos for this section, the ‘complimentary colour’ shots tend to mix both warm and cool colours, however I’ve picked out a couple of them which I think show ‘warm’ and ‘cool’.
While the background is green, there is a slight yellow/orangeness to it which – together with the yellow in the foreground – make the image appear warm.
In this one it’s the violet and green which appear cool – though there is a contrast with the yellow in the image.
Setting cool against warm creates and obvious, strong contrast and being opposites on the colour circle they balance each other. This kind of contrast is common in colours of light – e.g. sun near the horizon creates a warming yellow-to-red cast. Meanwhile, a clear blue sky has a cooling effect on subjects in shade.