I pressed it into a glass bowl and the puck was softer than I expected and the act of pressing caused the outer coating to break causing it to become a lighter shade. This did made it slightly thinner. I don't think being slightly thinner was the cause of the color change. I think there was a dark outer coating from age and by pressing the puck caused that outer coating to break away and get integrated into the puck. This caused it to lighten up some but still no where near white.