I think we're pretty sure that white is a colour.
I think you all are wrong. (I could be wrong too)
colours exist like numbers exist.*
You have black and true black. We know currently only one thing that shows (hehe) true black. A black hole! since it doesn't emit light.
If that black wallet on your desk would be truly black, you would see a 'gap' amidst your other stuff. We can safely say that any black in anyday life is a color, since we can see it. Truly black would be a gap. And even if it were truly black we could say the wallet had a colour. ->
1.Suppose you have seen only one color in life (a wall of white/green/whatever); there wouldn't be a concept colour for you, as you haven't seen anything else to relate to. Colors wouldn't exist if we hadn't two or more.
2a.I've read nearly all of this thread. only (about) 3 or 4 people mentioned that colour is a result of a wave.
2b. This isn't entirely true. By saying this, one implies:"registering a certain wave result in seeing a certain colour".
3a.*since color is a concept, a 'colour' (black** included) already was a color before we even saw them. Just like numbers, though an imaginary concept, already 'existed' before we even thought. imaginary is replaceable with virtual.
3b. We aren't aware of the concept 'color' since colour is much more natural than numbers. We constantly(***) see colour.
2c. Now i create a situation to this more clear
s(uppose)1: There are only for colours (black-red-green-white)
s2: There are 3 different creatures.
s3: Of the light spectrum those creatures can only register the three exact same frequencies. (the not frequency (absence of light),Hz1,Hz2,Hz3)
C(reature)1: (human like) sees black when there isn't any light. red when hz1. green when hz2, white when hz3.
c2: (human with rare color blindness; not really blind, it turns the colours around ->) black when no light. green when hz1. red when hz2. white when hz3.
c3: (xenomorph) red when no light. white when hz1. black when hz2. green when hz3.
So every creature above mentioned sees everything in the same form, but has not the same corresponding colour. Creature2 does indeed exist; there are people with 2 colour diseases (1: redwavelengt stays red, greenwavelength becomes red & 2: greenwavelength stays green, redwavelength becomes green) resulting in disease which turn around the colours. But it feels totally natural for them that everything green for them is actually red.
!!!!But it totally feels natural for them to say that black isn't a colour because their brains always have corresponded the absence of light with black.
Only because we evolved the same way, i may assume that green which i see is the same green you see.
colour is not an result of, it's in it's own right, so it can be used to 'label' an lightfrequency.
***not-truly-black is a colour. So everything around us has color.