Green is more than skin-deep for hundreds of frog species

The through-and-through greenness of hundreds of frog species that can be found deep in their lymphatic fluid, soft tissues and even bones, comes from a clever biochemical workaround that combines a normally virus-fighting type of protein with a toxic byproduct of blood breakdown. The camouflage innovation has happened at least 40 times across 11 families of frog and toad.