Use this http://188.8.131.52/IMEIQuery/IMEIQuery.aspx?ct=zh-CN
and you can see your build date. The Blue HTC One's I got from Verizon were built on 9/25/13. Month later than the one I got from Best Buy. Seems the blue ones are phones set aside by the manufacturer for warranty exchanges I think.
Left one is from Verizon right is Best Buy. Bit yellowish on the screen from Verizon but people are saying that will go away as it can be attributed to the adhesive. There seems to be no difference in games and videos for coloration.