I've obviously not put enough thought in to the sartorial elegance of my walking outfits. The colour just depends on what I happen to have on for the weather, or what layer is on show.
Cold & wet = red & black
Cold & dry = blue & red
Cool & wet = red & black
Cool & dry = blue & grey
Warm & wet = black
Warm & dry = blue
Hot & wet = black
Hot & dry = blue & red & green
Like most people I guess the colours have ended up accidental as I have bought things that suit what I want and what I can afford.