Mixing two RGB color vectors to get resultant

Question

I am trying to mix two source RGB vectors to create a third \"resultant vector\" that is an intuitive mix of the first two.

Ideally, I would be able to emulate \"re

Answer 1

I think you should really define what is "+" in your color scheme.

Based on your requirements, I've translated them into estimated hex color codes, (rgb represention can be deduced easily).

RED     + BLACK   = DARK RED  
#ff0000 + #000000 = #800000
RED     + WHITE   = LIGHT RED
#ff0000 + #ffffff = #ff8080

optimally, also with real paint characteristics:
RED     + BLUE    = PURPLE
#ff0000 + #0000ff = #800080
RED     + YELLOW  = ORANGE
#ff0000 + #ffff00 = #ff8000

I do not see a definite pattern which you can work out some formulas to achieve that.

John's and Nils' methods probably will come close to the colors but probably not to the exact values. I suggest you give theirs a try.

EDIT:
Updated the wrong color codes. Well it does made a lot more sense now.