[SAJ]

Red, yellow, blue are the primary colours of pigment. The secondary colours are the pairwise combination of the primaries. On the so-called 'color wheel', a primary colour and the secondary colour opposite are called "complementary colours", thus, orange with blue, yellow with violet and red with green. Sorry, but the 'opposite' of yellow is violet (combo of red + blue), not blue (blue is primary, right?).

The combinations for coloured light are different, and the concept of "complementary" in light is considerably different.

In the UK (can't speak for the US), blue + green pigment yield a colour called cyan, considerably darker than typical turquoise. Same name for blue + green light, cyan, but somewhat lighter than pigmentary turquoise. I can't vouch for what these colours may be called in the US (the pigment, I should think, would be called blue-green, somewhat a la the crayon colour...but I'm guessing).

You might Google "complementary colours" (or no 'u', ahem) to learn quite a bit about the relations and combinations of pigment, and perhaps about light as well.

FReegards!

[null and void]

I was going with RGB light not YMC pigments.

I further abstracted it to perceived colors, as in red-green are a color receptor pair, as are blue-yellow. (Based on the flavors of color blindness). IOW, I pretty much made if up as I was going along...

Besides, I’m a guy. We can only name 5 colors...