Liquid colors impart a rich and texture to any cosmetic product that they are added to. Liquid colors are highly concentrated and need to be diluted when used.
The main reason for using liquid colors in cosmetic products like soap or lotions is that they do not change the consistency of the product. All they do is just add a pleasant color to the cosmetic product.
This would create a cosmetic product that can be associated with a certain theme. For instance, when a lemon-yellow liquid color is blended with a lemon-flavored oil, a refreshing and indulgent beauty product would be created.
One thing to note about the use of liquid colors is that if too much color is used it can alter the color of the lather and the bubbles formed. It would also impart an unpleasant residue on the skin when used in a lotion. Few drops of liquid color are more than enough for making most of the cosmetics.