color = {r=1, g=0, b=0, a=1} -- red, full opacity color = {r=1} -- the same red, omitting default values color = {1, 0, 0, 1} -- also the same red color = {0, 0, 1} -- blue color = {r=0, g=0.5, b=0, a=0.5} -- half transparency green color = {} -- full opacity black