Best sights I've found are Ameriglos for SIG and the yellow/green front.
Next best is Truglo Trit Pros. I wish they had the yellow fronts, but I choose white over orange. Orange often gets washed out. I guess if you are shooting guys in white outfits it doesn't work, but its better than orange/red for me.
I DO find them useful in low light - the front sight with the white insert seems to glow much brighter than the rears so you stay oriented on the right thing. They also don't dominate the target, so in low light they are best. Total dark needs a light.