This may be an old wives tale but there's a reason why we've all heard this one before. In the past (around 10 or more years ago) at home and even professional color had a lot more ammonia in it then they have now just to get that proper lift, anywhere from 6-10%. Now it's an average of around 2% to 0. With a higher ammonia content it would make sense to jump to the conclusion that the natural oils provide a buffer from the burn or sting of ammonia. Some stylists use Sweet n Low to numb the burn of chemicals and it does work however the burn is telling us something important; that there's a potentially serious chemical reaction happening and it may need to be removed ASAP. Also, in the past "dirty" hair meant 1 - 2 day old hair, these days in our dry shampoo haze that could be anywhere from 3-10 days with a lot of extra buildup. Product buildup can prevent color from getting into the cuticle and could come up "spotty" or uneven. Basically the idea behind this saying is to not overly disturb and irritate your scalp (by hard brushing, scratching, using harsh products... etc) the night before your color appointment. It might also have been born from stylists frustrated with baby fine and very clean hair that is "hard to handle" by way of putting into foils, etc.. (-suppressing my urge to eyeroll-) These beauty "tales" are almost always born from good intentions however when given enough time to take flight as a common saying among the masses without any proper explanation or further examination as to why we think this is true then it becomes a problem. I've been guilty of carrying this one on as well. That will no longer be the case and I want to shout this one from the rooftops and have it reach everyone far and wide. Color does not perform better on dirty hair. In fact, clean hair is the absolute, hands down, best choice to have for the perfect canvas for coloring. If you have a sensitive scalp or are worried about it there are MUCH better options than leaving your hair dirty for a week or two before your color appointment (all of which I offer in the studio so you don't have to worry about it) 1) There are specific serums/oils made for use right before chemical services. 2) There's a product called AntiDotPro that's an additive made for chemical services. It's an antihistamine so it doesn't numb out or cover up the burn of a chemical, it prevents you from having a reaction altogether. This stuff is absolute gold for anyone who has scalp sensitivities. 3)Protect and baby your scalp by not irritating it prior to your service. I also offer treatments that will remove any and all buildup to your hair and scalp. Share this with your loved ones! <3
Edited to add: Please keep in mind!!
Scalp stimulation is very healthy and we need that blood flow! That's why it feels so good to have our heads scratched or shampooed. The advice I'm giving above is ONLY for prior to a chemical service.