humm.. Not All reptiles has red blood....
"Papua New Guinea is often billed as ‘The Land of the Unexpected’ and it is certainly that. Five small species of skinks with green blood are found here, the only green-blooded land vertebrates in the world. "
Found on the Mark O'shea 's website:
"In 1968 research into the blood of green-blooded skinks determined that the colouration was due to the presence of a biliverdin-type pigment, like that found in bile. Mark has a theory that this may make the lizards taste bitter and deter predators, a once tried, never repeated experience for lizard-eating birds."