@umbra21 - I actually find that really disappointing! I liked the idea of bright blue blood for some reason. And it seemed quite intuitive that it should be red when it's got oxygen combined with the iron in red blood cells (like rust is red, oxygen plus iron seems to equal red) and blue when there is no oxygen present.
Although I guess when I really think about it, most body systems seem to be reddish (not that I've got lots of experience with them!), so there is no reason for blood to be an exception.
It just seems kind of boring for erythrocytes to be naturally dark red instead of bright blue.