Hair color can be lightened by using clarifying shampoo. To avoid hair coloring mishaps, it is best to transition to the desired color gradually.
Depending on whether the dye used is permanent, demi-permanent, semi-permanent or temporary, clarifying shampoo can remove at least some of the pigment after a recent dye job. They contain color-stripping agents and work best if used as soon as possible after the dyeing process. Applying heat during the process is also helpful, as it opens up the hair shaft to allow the product to be more effective. Following up with a conditioning treatment is highly recommended as dyeing and clarifying shampoos can both cause dryness.
Lemon juice and certain leave-in products may also be used to lighten hair by applying either of the two generously to hair, then exposing it to the sun or a heat source. This technique works on both natural and artificially colored hair, although the resulting tone is not possible to control and may result in unwanted brassy hues.
If at-home methods do not help, it is best to consult a professional at a reputable hair salon. This is especially true for someone who wants to use lighteners and color removing agents as these can be quite damaging.