May 18, 2018knowledge, opinions/rants, technologyadditive color mixing, blue, color primaries, green, subtractive colour mixing, yellows.westland

So some civilization say yellow and blue make green. And also you will discover other answers that say the yellow and also blue do black. How can this be?

Well, we need to recognize a small science to get to the bottom of this.

You are watching: What color does blue and yellow make

The figure below shows what happens as soon as you mix suitable yellow colours with perfect blue pigment. The blue dye mirrors light perfect in about a third of the spectrum (and absorbs perfectly in the other two thirds). The yellow pigment shows light perfect in about two thirds of the spectrum (and absorbs perfect in the other third).


Notice that v a genuine yellow colorant, that does no reflect perfectly in the middle and also long wavelengths and it does not absorb perfectly in the brief wavelengths. That reflects and also absorbs to some extent all the wavelengths however it absorbs an ext the much shorter wavelength and also absorbs less the middle and also longer wavelengths. The same is true of a real blue pigment; that does no absorb perfect at the middle and also longer wavelengths. The consequence of this is that you don’t get black if you mix blue and yellow. Girlfriend would acquire black if the pigments to be ideal however they room not. We live in the actual world. However, you certainly don’t get a beloved bright eco-friendly as shown in the colour wheel v red, yellow and blue primaries. Girlfriend would acquire a dark desaturated murky dirty greenish colour.

Now let’s see what happens as soon as we mix cyan and yellow. We’ll begin with the best colours.


That’s right. Mixing cyan and magenta makes blue. The cyan absorbs in one third (the red third) and also the magenta absorbs in one third (the eco-friendly third) yet neither absorb the brief wavelengths.

So ultimately you have the right to see that the finest subtractive primaries are cyan, magenta and also yellow due to the fact that the cyan is red absorbing, the magenta is green soaking up and the yellow is blue absorbing. And what is more, friend now know why this is the situation (rather 보다 accepting dogma). You likewise understand why there is a relationship in between the CMY the subtractive mixing and also the RGB the additive mixing.

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John R Reinert Nash says:

This post focuses on pigments, and also why CMY make an ext logical primaries because that pigments. The explanation is solid (as any kind of press printer will tell you!), and the RYB wheel together something taught in elementary institution art course really does need to be updated. If we can acquire these males to do a video on CMY, it would certainly go a long way:

together a color scientist that straddles the human beings of image capture (RGB!) and also print (CMYK and more!), however, we have to absolutely proceed to teach the yellow and also blue do green, yet make that clear that this works for light, and not so well for paint. Ns recall the Kodak go dabble in CMY color filters because that a digital camera, however RGB filters (Bayer filter in particular) because that light really do seem to have actually won the day because that camera capture (with some amazing experiments in including an “emerald” 4th pixel color by Sony that never quite seemed to take off).