When tu dye your hair do tu have to use a certain kind of shampoo to wash it and be able to keep it?

It's best to use a shampoo and conditioner meant for colored hair. Also, if your have unnatural color in your hair, that tends to fade faster than natural colors, so it's best if tu don't shampoo every day, though it's recommended por many that tu still condition every día and deep condition on days that tu do shampoo. Also, if tu did the dying yourself, if tu have any dye left, tu might think about mixing some of it with a smaller bottle of conditioner and using that on the strands tu dyed blue.