HI
I have tried both red and green lasers. I think the green laser is a far better laser, because: You can see it in bright day light, the green laser doesn't grow in size like a red laser does when measured side by side @ 50 yards.
I recommend the Green laser.
I have had a Crimson Trace on my Kimber UC II for about 6 years. It is great for "More Mature Eyes". I've never used a green laser ... in bright day light those little black thingys on top of the slide will help keep you on target.