Fiber Optic Sights
Many of the fiber optic sights it's not that hard to replace the fiber optic rod/pipe and the rods are very inexpensive and in that case I wouldn't worry too much over the initial color. If you don't like it you can change it. Check Speedshooterspecialties who have a forum here. They sell Red, Green and Yellow at 50 cents an inch.
I have front red FO on my new M&P (Dan Burwell installed), Hi-Viz Red on my Glock 34, and TruGlo's TFO's front and rear which in TFO I believe only come in green on my Glock 19. TFO's are Fiber Optic and Tritium combined. I really love those sights and hope they come out with for M&P.
I do like the red for outdoors, but they are not that good for indoors though I'm too lazy to change till the rod breaks just for plinking.
I have learned from the HiViz which do break occassionally to always carry extra rods in the range bag. I've yet to have the TFO's break and I have carried the gun.
Except for the TFO's or Overmolded Hi-Viz (mine aren't) I wouldn't use FO's for carry since they can break.
I did note that HiViz now has an overmolded M&P sight available. http://www.hivizsights.com/Smith-Wesson-M-...ght-P120C9.aspx
BTW HiViz says you cannot change the pipe in their overmolded sights.