From Garry's Mod
Sets the player model's color. The part of the model that is colored is determined by the model itself, and is different for each model.
This is the color to be set. The format is Vector(r,g,b), and each color should be between 0 and 1.
When a player spawns their color will be red.
function GM:PlayerSpawn( ply ) ply:SetPlayerColor( Vector(1,0,0) ) end
local function SetColor( ply, color ) ply:SetPlayerColor( Vector( color.r / 255, color.g / 255, color.b / 255 ) ) end