[SAMURAI16]

instead of creating 4 cvars (sm_tank_colorer_red,sm_tank_colorer_green,sm _tank_colorer_blue,sm_tank_colorer_alpha) I suggest you to create one cvar, something like sm_tank_color and to be in this format "r g b alpha"
And you'll use for example sm_tank_color "255 100 255 255"