... or UV light 2.Change form :transparent --vivid color --transparent 3.SGS,MSDS TEST 1.photochromic pigment :Under ... Ultraviolet light or sunlight .color change from white color or very light color to RED ,YELLOW,BLUE ,PRUPLE color .Once away Ultraviolet ... again and agian .2.Basic color : Red ,Yellow, Blue ,Purple (after changing color form )3. Change form : White to red color Color-changing pigment