uniform sampler2D samp9; out vec4 ocol0; in vec2 uv0; void main() { vec4 c0 = texture(samp9, uv0); // 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; ocol0 = vec4(red, green, blue, c0.a); }