Oh right, yeah. You'll want saturate(a), rather than a inside the lerp then. Can't do clamp outside when defining a otherwise you're clamping a value that needs to span a range of 2. float a = color.a * 2;float r = lerp (color.b, color.g, saturate(a));a -= 1;r = lerp (r, color.r, saturate(a));