First Get Gibs Save editor.
Hit the Raw tab and scroll down to Squad -> Player -> Appearance -> Morph Head -> Vector Parameters. Click the [...] button and another window will open.
On the left side of the second window, find the EYE_Iris_Colour_Vector entry. (It's number five on the list, at least for me.) Then, on the right side, hit the plus sign next to Value. The menu will expand. The R, G and B entries are for red, green and blue, and presumably go from 0 to 255 (but I haven't tested going higher) and higher numbers mean more glow. The character in the pic above has B 228, G 6 and R1.
Right below that one, you'll find HED_Hair_Colour_Vector. As you may guess, it controls hair colour (the character in my pic has a 1 in every field for white hair).
I believe the default values are all below 1 (typically something like 0.431212), so anything from 1 and above may have a tendency to look glowy under certain conditions. But then again, that may be exactly what you want.
