# try with:
# frontcolor - red, alpha = 12
# backcolor - yellow, alpha = 3

dx = (2.0 * x/width)-1.0
dy = (2.0 * y/depth)-1.0
dz = (2.0 * z/height)-1.0

d = random.NextDouble()
front = (frontColor.R, frontColor.G, frontColor.B, frontColor.A)
back = (backColor.R, backColor.G, backColor.B, backColor.A)

if dx**2 + dy**2 + dz**2 < 1.0:
	return Color( *[(d*(ff-bb))+bb for (ff,bb) in map(None,front,back)] )
else:
	return empty