I believe Santa wears red because
1.He wants to be noticable so other flying sleighs don't crash into him
1 1/4. because is he dressed in white no one would be able to find him
2.because green makes him look fat
3.Because in his off time he is a Roman warrior who needs to intimidate his opponents or to scare off his evil German twin Knecht Ruprecht unbeknownst to him by the time he gets to Switzerland he shall realize that his evil twin is really his other personality as he has multiple persolality disorder.
4.Santa wears red?
5.To make rudolf less insecure
51/2.For the sake of coca cola!
6.Because on his off days he is wears Waldo <.<