This is Fatty, my 15 year old Phelsuma madagascariensis grandis, or geico gecko as they are known nowadays.
Fatty, like almost all grandis geckos, is lime green with red spots on his back and red markings on his face. However, he's been outside for a week or two and it's currently very sunny in Southern California. When he's suntanned, his skin is blue.
I've never seen a blue grandis before - the intensity of the color rivals that of my Phelsuma guimbeaui, Heidi. I don't have a picture of Heidi because he is aptly named and I've never gotten near him with a camera in my hand.