L.A. Colors Cream To Powder Foundation - Nudecolor NudeBlend it like its hot! The L. A. COLORS Heat Activated Blending Sponge changes color when activated with warm water. Using a warm sponge mimics the warmth of blending in makeup with your fingers to smoothly melt products into the skin for a flawless, natural finish. This unique heat activated sponge changes color to let you know when your sponge is warm and ready to use. Simply run warm water over the sponge, and squeeze a few times, then pat it dry