Define, check and (automated) correct string-values for the tag "colour" (for buildings, ...)

[Mateusz_Konieczny]

added, will run probably earlier today after I finish things I am supposed to be doing today

I skipped DeepSkyBlue (545) vs deepskyblue (63) and DeepPink (2) vs deeppink (26)

DeepSkyBlue seems way more readable than deepskyblue AND is more popular.

@Fizzie41

red;white (4k), red/white (3k), red_and_white (2800), red-white (921), white;red (574), & white-red (356) which should probably all be one option only?

if something has white and red stripes it seems reasonable