Thermochromic (color change with heat) PU faux leather material.  When heat is applied (or the surrounding environment is hot enough, ~75F), the striking blue upper layer begins to vanish to reveal a vibrant pink color underneath.    

** Now with Microfiber backing!!

* WARNING - The integrity of the color changing effect is not permanent.   Over time the return to primary color (ie black) will diminish and the color may appear dull.  It should remain strong for a longer period of time if you do not leave it in direct heat (ie blazing hot sun) for hours at a time.