The tortoise beetle's shell has several layers that, when modified, can reflect light differently and change its color. The beetle normally changes color when it's disturbed by an external stimulus. The framework behind this piece of jewelry's color change is still not entirely understood.
The stoat doesn't have special color-changing skin cells like the chameleon, but it does change into a different outfit depending on the season. Although it's usually reddish-brown with a white underside, during the winter its coat becomes white with a black tip on its tail. What the stoat lacks in color-changing chromatophores it makes up for in cuteness.