"Don’t apply it on dry because the hair is more porous and it will grab too much of … You can experiment with using watered down purple shampoo, or purple shampoo mixed with regular shampoo, if you’re not wanting to brighten and cool down your tones too much. Keep in mind that purple shampoo does not replace your regular shampoo and should only be used once or twice a week. General recommendations for using purple shampoo. Doss warns that there is such a thing as too much purple. “When you eliminate too much yellow, it visually ends up darker and a lot of people don’t want it … But if what you want is simply to get rid of some yellow pieces, the best is to use the purple shampoo on wet hair and for less than five minutes. Even though people decide to use purple conditioner, my friend discovered that her … My friend learned that to get the most out of purple shampoo, it’s essential that you know your hair well before identifying your problem areas that would benefit from a purple toning shampoo. Those are the areas where you should apply the purple shampoo. To use a purple shampoo, wet the hair and lather on the formula. If you’re using purple shampoo as a casual, subtle toner – use a small amount after clarifying your hair with a regular shampoo. You can also apply just pea sized amounts of purple shampoo to known problem areas, if … You should let the purple shampoo sit in your dry hair for twenty minutes, always observing how it reacts.