Always strand-test the hair prior to a full-color application. Use permanent hair color on human hair unless the hair is porous, in which case semi-permanent color is the better choice. The same rules that guide the colouring of natural hair also apply to the art of coloring wigs and hair extensions. If you are going to custom color the hair, use hair that has been decolorized (bleached) through the lifting process, not with metallic dyes. Be sure to check with the manufacturer. No company will guarantee their hair when you have processed it; there are just too many variables.

• Select the hair with the closest color to the color you want. Always select the same or slightly lighter color, never darker. Hair extension hair can be very difficult to lighten if it is any color except virgin color #1,#1b or #2.
• The hair needs to be banded loosely with an elastic. You will have to work the color up under the elastic. Wash the hair first with a mild shampoo and pat dry but leave damp. (Dry hair will “suck” the color up and be uneven)
• The toner (color): demi-permanent color works the best with a very low developer. If you are toning blonde hair mix clear into the color if available. For blondes, a purple shampoo may be enough for toning.
• Work the color thoroughly into the hair using a colour brush-you can also pick up the bundle and work it in with your hands. Be gentle with the hair make sure you don’t scrub. Get the color under the elastic or you will have a missed spot on the strands. 
• Extension hair can process color faster than the natural hair on the client’s head because the extension hair can be porous. It can also process slower because there is no heat. Keep a close eye on it. If it is slow, wrap in plastic and warm with a blow-dryer.
• When processed, wash gently with lukewarm water and a gentle shampoo. Work in a very light conditioner, rinse again. DON’T GET ANY CONDITIONER ON THE KERATIN!
• Let dry on a towel, (overnight if possible), dry gently with a blow-dryer or hang under a hooded dryer. Flat iron the hair after drying to smooth and make it easy to work with.

Tips on Maintaining a Client’s Hair Color with Hair Extensions

Your clients can have hair color, highlights and extensions too, just follow these tips:

• Color the clients roots approximately 3 days before the extension application. This will let any residue or swelling leave the hair and prevent extension slippage. (This is especially important with keratin/fusion extensions). This will also give you four or more weeks of growth before the next touch-up, making it easier.
• When doing a touchup avoid the bonds as much as possible but some color on the bonds will not hurt them.
• Foil highlights can be done on the crown top and sides and between any extensions. Extensions themselves work as highlights
• MAINTAIN A MOISTURIZING CARE SCHEDULE. It’s always important to keep the hair moisturized, however, color-treated hair will need extra care. A sulfate-free deep conditioning treatment on the extensions after toning to ensure that any lost moisture and nourishment is added back into the hair. If possible, leave this on overnight for the best results. Deep conditioning bi-weekly (or as needed) and using products that are specifically formulated for dry and damaged hair, as they will help keep the strands healthy and nourished. Also, look for products that add moisture to the hair like argan oil, coconut oil, castor oil and so on.