There are two sides to the debate on whether hair colour holds better or worse on greasy hair.
Some people recommend leaving your hair dirty and oily before using hair dye. It apparently makes the dye attach to your hair better and look more vibrant. Others say you should have squeaky clean hair not just to avoid disgusting your hair dresser but also to make it easier for the colour to spread evenly.
The truth, according to many hair care experts, is somewhere in the middle.
Oily hair before colouring: Is it okay?
So, can hair colour be applied on oily hair? The simple answer: to some extent, it’s okay and even recommended.
The long answer…
Your scalp produces natural oils called sebum. The oils coat your hair, making it soft and protecting it from many things like pollution and chemicals. Some people produce more sebum than is usual resulting in naturally extra-oily hair.
But it’s not just sebum that coats your hair and scalp. Oils and other ingredients from your hair products also build up especially if you go for some time before shampooing. There will also be layers of dust and dead skin cells.
Then there is the hair colour. There are many different types and formulations of hair dye. Most contain chemicals that can potentially irritate your scalp and cause some damage to your hair.
In fact, one of the arguments for leaving your hair greasy and unwashed before colouring is that the oils protect your hair and scalp from damage and irritation.
That’s somewhat true. If your hair is too exposed – that is, if you deep-wash it too close to the dyeing session – it will sustain more damage. You may also feel discomfort and irritation on your scalp from the ammonia and peroxide in the dye.
Some hairdressers also say that too-clean hair is harder to handle. It’s more slippery, making it more difficult to colour and reduces the dye’s ability to hold.
But too much greasiness can also be a problem. For permanent hair colour to work, it needs to penetrate inside your hair shaft. Temporary hair colour also needs to be able to hold onto the exterior of the shaft.
Too much sebum combined with layers of dead cells and old hair products can prevent hair colour from interacting well with your hair. Permanent dye is unable to get inside the shaft while temporary dye spreads unevenly.
Your hair colour won’t look good. It’ll either look blotchy or appear faded.
How to prepare for hair colouring
Do not let your hair get too greasy and dirty but don’t over-wash it. Too much oil will ruin the dye job while scrubbing it clean will expose your hair and scalp to damage.
The best thing to do is wash it on the evening before you get it dyed. Washing it a couple of days before is alright too especially if you do not have naturally oily hair. Use a gentle shampoo for oily hair that will remove any dirt and excess oils but won’t leave your hair dry and exposed. Your hairdresser may also advise you to just rinse your hair without using any shampoo.
Gently washing your hair a day or two before colouring ensures that it’s clean enough for the colour to hold but not too exposed that colouring will be painful. There’ll still be some oil to protect your hair and scalp.
If the dye label directs you to wet your hair before application, make sure you just rinse, not shampoo, your hair.
My hair gets greasy fast, What do I do?
For those with extra-oily hair that gets greasy overnight even after washing, there are a few ways you can keep the oiliness down for the colouring process.
First, do not fuss with your hair. Brushing and scrubbing too much leads to more sebum production, not less. After washing it, you can pin it up and let it rest. Fussing with it might also transfer oils from your hands to your hair.
Another effective trick is to use baby powder. It’s gentle so it won’t affect how well the dye holds. Just sprinkle a bit of it especially on your roots and gently brush it across your hair. It will absorb excess greasiness before you get your hair dyed.