line 274
doColorShift = true;
colorShiftColor = "0.118 0.11 0.128 1.000";
change colorShiftColor to the purple color you want
it is RGBA on a 0-1 scale
I took the liberty of translating your purple into RGBA that you included inside the zip
and then divide each number by 255 to get it on a 0-1 scale
any texture image that is at least partially transparent will blend the color shift color with it, if you do not want to utilize color shift do not use textures that are partially transparent, ie black25 black50 blank etc.