2

Why RGB instead of BGR, GBR or perhaps GRB?

Why CMYK instead of YMCK, KMCY, CKMY, YKMC and etc?

  • 2
    "Why CMYK instead of YMCK, KMCY, CKMY, YKMC and etc?" Why not CMYK? "Why RGB instead of BGR, GBR or perhaps GRB?" Why not RGB? – Michael C Jul 29 at 21:54
  • 2
    If i answer correctly can i pass over the bridge ? – Alaska Man Jul 29 at 21:55
  • @AlaskaMan Is this from the original LEGO movie which I have watched when I was a child? – Delta Oscar Uniform Jul 29 at 21:57
  • 1
    @ Oscar, Your quest is to seek the Holy Grail. Ask Monty Python. – Alaska Man Jul 29 at 21:58
  • 3
    It's pure convention. I've seen different ones used by knowledgeable folks in different context. – Stan Jul 30 at 0:18
3

I presume RGB is in that order simply because it is the common spectral order — RoyGBiv, in other words. You will sometimes see BRG or otherwise when a particular computer image format happens to store the channel data in that order.

CMYK, on the other hand, is that way because that's the order the inks are normally applied in process color. See for example this article on four-color printing.

  • Now the question becomes "Why CMYK is applied in CMYK order" – Delta Oscar Uniform Jul 29 at 22:04
  • 2
    That I don't know. It might simply be that that order is the order of the complements of RGB, and that became convention. But there may be something about the color mixing properties. – mattdm Jul 29 at 22:07
  • 3
    The "laydown sequence" or sequence is not a rule. The press operator can choose any order for any number of reasons. K in the sequence taken for blacK takes its name from "Key" which to a pressman means first down. The first down hue is chosen such that subsequent inks can be registered with the first. Cyan is also used as a key as it is easy to see. Yellow would be the worst. The lighting in the pressroom is often bluer than you might want so that yellow on press can be more easily seen. – Stan Jul 30 at 0:14
  • Spectral order still depends on whether one reads from right to left or left to right, or starts with lower frequencies or lower wavelengths. – Michael C Jul 30 at 0:51
  • 1
    In science, maybe. In popular culture, I'm pretty confident that "red orange yellow..." is rainbow order. – mattdm Jul 30 at 8:16
3

Perhaps it’s as simple as the positions occupied by the colors on the spectrum.
enter image description here

  • Na, that would be too easy – Alexander von Wernherr Jul 30 at 7:42
  • 3
    Generally filters pass their name and block their complement. A red filter passes red and blocks cyan. A green filter passes green and blocks magenta. A blue filter passes blue and blocks yellow. A cyan filter passes cyan and blocks red. A magenta filter passes magenta and blocks green. A yellow filter passes yellow and blocks blue. Red Cadillacs BY General Motors was commonly used. Red – Cyan Blue – Yellow Green – Magenta. In printing, black results when C+Y+M overlap. This black is too weak. Black ink is added to boost the contrasts. The black is called a Kicker thus CMYK. – Alan Marcus Jul 30 at 14:51

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.