uniform half4 colorGreen, colorRed;

half4 main(float2 coords) {
    bool4 inputVal = bool4(colorGreen);
    const bool4 constVal = bool4(false, true, false, true);
    bool4 expected = bool4(true, false, true, false);
    return (not(inputVal.xy)   == expected.xy    &&
            not(inputVal.xyz)  == expected.xyz   &&
            not(inputVal.xyzw) == expected.xyzw  &&
            not(constVal.xy)   == expected.xy    &&
            not(constVal.xyz)  == expected.xyz   &&
            not(constVal.xyzw) == expected.xyzw) ? colorGreen : colorRed;
}