void main() { float4 c0 = Sample(); // Same coefficients as grayscale2 at this point float avg = (0.222 * c0.r) + (0.707 * c0.g) + (0.071 * c0.b); float red=avg; // Not sure about these coefficients, they just seem to produce the proper yellow float green=avg*.75; float blue=avg*.5; SetOutput(float4(red, green, blue, c0.a)); }