the leuco dye is the main materials of thermochromic pigment or powder , its white colors , purity could 99% , more hight purity more white. with the other two ( color developer and sensitizer) makes the thermochromic powder used in the paints , ink and other materials . it comes differnet colors on differnet temperatuer. and it will back it's original colors if the tempertuer back . CAS RN 75805-17-3 CAS RN 98660-18-5 CAS RN 142199-90-4 CAS RN 36499-49-7 CAS RN 87563-89-1 CAS RN 114090-18-5 CAS RN 69898-40-4 CAS RN 21121-62-0 CAS RN 22091-92-5 CAS RN 26567-23-7 � CAS RN 50292-95-0 CAS RN 26628-47-7 CAS RN: 50293-29-3 CAS RN: 50292-91-6 CAS RN: 21934-68-9 CAS RN: 565457-61-6 CAS RN: 132467-74-4 CAS RN: 38880-20-5 CAS RN: 54574-00-4 CAS RN: 21528-30-3 CAS RN: 75805-17-3 CAS RN: 142199-90-4