THANK YOU!
The file I was looking for was the ColorDeficiency.ush which contained three lines that saved my life:
// CDV tables comes from:
// A Model for Simulation of Color Vision Deficiency and A Color Contrast Enhancement Technique for Dichromats
// - Gustavo M. Machado (2010)
for others who are doing academic research around color blindness/deficiency, the file is located in your engine install path \Engine\Shaders\Private