I have read that deer see in shades of grey, same for most animals except birds. Also that they see some of the Infared spectrum so any brighteners in washing powder makes clothing glow like neon signs to most animals. How true I do not know but have better success at stalking in close with clothes, plain and camo, not washed with brighteners.
The primary functions of Camouflage clothing is to break up the human form and to blend in with the surrounding bush. So some of the straw coloured clothing should work in dry savannah grass lands. I know the Australian Army Poly uniform shirts work well in these situations.