I am inquiring about the Glock XS standard sights. Do they offer the sights with a green front and yellow rear? I am aware that there is quick front sight acquisition with the XS sights, but I am concerned about using XS Sights in low light or no light situations. Being that both night sights are green, under high stress it may become difficult to discern which sight is the front sight. I am definitely considering the XS sight system but the lack of Green/Yellow combinations is causing reservation. Also, Do you put these sights on yourself? or do you take them to a gun shop to install? I have never put on sights on any of my pistols because I do not have the equipment. Thanks.