Makeup has been a body decoration process for self expression and transforming one's appearance. While the material composition and processes for creating makeup products have evolved, they still remain static and noninteractive. However, as our social contexts demand different representations of ourselves, we propose ChromoSkin, a dynamic color-changing makeup system which gives the wearer ability to seamlessly alter their appearance. As an initial exploration, we prototyped an interactive eye shadow tattoo composed of thermochromic pigments which are activated by electronics or ambient temperature conditions. We present the design and fabrication of these interactive cosmetics, and the challenges in creating skin interfaces that are seamless, dynamic, and fashionable.