I belong to a indoor shooting range with a 100 yrd range. I tried shooting at 100 yards with my surplus rifles with iron sights and the lighting is not good enough for me to get the front sight lined up with the rear and still focus on the target. Using the same rifle and target outdoors is not an issue. My targets are about 8" solid circles either red or black. Any tips on painting the sights different colors or using different targets?