_ref _green _blue????????

I have used a DFDY filter on a raster map. My problem is I've
produced
3 raster images from the filtered image called "linear dfdy" which
are
"linear dfdy_red", "linear dfdy_blue", and "linear dfdy_green" and
these images are astoundingly cleared and enhanced! But I didn't
remember the Functions or Operations I've used to produce this
images.
Is there a function or operation in ILWIS that can enhance image by
some "red", "green", and "blue" input??? Can somebody figure out what
function could that be??? Please. Thank you. (Actually, I've
accidentaly used that function without remembering it, therefore
producing accidental enhanced image.)