I've tried all the florescent colors, and for me, I find white works the best under all lighting conditions.+
Just after I got my 1911, put a small drop of Liquid Paper on a toothpick and made a clean white circle on my front sight.
If I didn't tell you I did it, you'd think it was that way from factory.
Made a huge difference
(the rear sight is adjustable and all black)
Thinking of getting some florescent green paint & doing the same on a couple other pistols.