I have realized all my peers even some of my teachers believe humans have blue blood. My whole life I have been told that the deoxygenated blood was blue. Then when our blood has oxygen it is red. To prove how my blood is blue. They told me to look at my veins. Our veins are blue. Well this is a myth. Our blood is NOT blue.
Our blood will always be red. Blood is red because it is full of red blood cells. Deoxygenated blood is a dark red color. While oxygenated blood is bright red.

Here are some links to get a better understanding. You'll find out a lot of the things you have been told growing up isn't always true.
http://chemistry.about.com/od/biochemistry/a/Is-Deoxygenated-Human-Blood-Blue.htm

http://scienceline.ucsb.edu/getkey.php?key=3964  <- this link here i highly recommend looking at.