blue hue on side of screen... whats up?

[TMCM]

My friend has a Sanyo Z3 projector. It has had lots of use but what I am wondering is if this means the bulb needs to be replaced or if the screen is crapping out. Notice the blue hue on the side of the screen where it shoudln't be? Whats up?

See pix

www.juxsa.com/z31.JPG
www.juxsa.com/z32.JPG

Thanks