Though it isn't a new technique, color-correcting makeup has surged in popularity over the past few years. The concept is simple: it plays upon the color wheel from your elementary school art class.

Procter & Gamble (P&G) has launched Crest Kids Color Changing Toothpaste and a line of Oral-B color-changing themed toothbrushes. The bubble gum-flavored toothpaste changes from blue to pink after two ...