Answered this in reddit, but in case anyone else is interested:
It varies. Mostly HSV, but occasionally plain ole RGB. I think though you're getting caught up on the fact that the game (for the most part) defines color parameters in a numerical percentage of a value.
English translation:
Using your example, if we're talking RGB and color = { 1.0 0.4 0.4 0.2 } then:
1.0 = 100% of 255 = 255
0.4 = 40% of 255 = 102
0.4 = 40% of 255 = 102
0.2 = 20% of 255 = 51 on alpha.
So this color would be R:255 G:102 B:102 A:51 which is a lovely shade of coral (#ff6666 in html if u want to look it up)
If we're talking HSV and color = { 1.0 0.4 0.4 0.2 } then:
1.0 = 100% of 359 = 359
0.4 = 40%
0.4 = 40%
0.2 = 20% on alpha.
So this color would be H:359 S:40 V:40 (R:102 G:61 B:62) which is somewhat ugly shade of redish brown (#663d3e in html if u want to look it up)
