I'm guessing you meant that last bit to be "A:0.0 = B"? If not, replace color.b in this code with 0. Something like this should work... float a = color.a * 2; float r = lerp (color.b, color.g, a); a -= 1; r = lerp (r, color.r, a); You could branch it... but I suspect lerping is easier on the shader. They still don't really…