Whats up with blue and red 13 and 14?

Can some one tell me what blue means and what does it 13 number mean, and what meaning red and its 14 has towards gang members? I had it already you can't go out wearing red or blue cause you'll get shot. Not long ago two kids got shot one of them died the other made it to the hospital but died a few days later. The kid who died that same day he got shot, if that wasn't enough his mom and sister got killed too for no reason. Gang members of the opposite side followed his sister and mother and killed them and they have nothin to do with what ever was going on. The mother didn't even knew her son was death. A friend of mine got shot accidently by a lost bullet, some gang members were trying to kill someone else and my friend got shot for no reason, he was sitting on his car waiting for his brother to come out of the store when a group of gangsters were shooting at each other, well one of those bullets hit my friend. So can any one tell me what the F*ck is it that they're fighting for? I don't get it.