That color is not normal. Chameleon coloration is neurohormonal (meaning the chameleon can control color with hormones/moods but the neuronal component must be intact) so it may mean that the nerves going to that leg were damaged as well as the bone. In chams with spinal injuries sometimes the whole body behind the fractured spine segment has distorted coloration due to nerve damage. Probably means it was a significant break. Looks like it's covered in scars/bruises so who knows what it's been through. May have been an overzealous collector ripping it off a branch. If the abnormal coloration was more diffuse and not localized to what looks like the distal portion of the limb I would be concerned about sepsis and spreading infection. From what I can see in the blurry picture it's confined past the knee, which would indicate the nerve damage is local to the leg, but it's a little hard to tell. IF the coloration expands or you see it elsewhere that could indicate a systemic infection much more serious than just a broken leg. The coloration may not ever be normal to that leg. Do you have a better picture? I can't see the break from that one...