I'm looking to change my hair colour at home, but am not sure of the differences or benefits between demi, semi and permanent.
The formulas differ in that they contain varying levels of ammonia or peroxide that translate into how the colour is deposited into the hair shaft and how damaging they can be. Demi- and semi-permanent colour can't lighten your hair in any way, but they deposit colour onto the hair.
They contain very low levels of peroxide (sometimes none) and won't penetrate deep into the shaft, meaning that, within six weeks or so, the colour will wash out completely. Permanent colour contains a higher level of peroxide. It can lighten the hair and deposit new colour onto the shaft. With that higher level of peroxide or developer, you gain a more permanent colour that doesn't wash out (although it may fade over time).
The downside is you risk more damage thanks to the higher level of peroxide used. If you are looking to lighten or darken your colour by more than one shade, I'd suggest seeking the help of a pro.
Bahar Niramwalla is a celebrity makeup artist and beauty specialist on The Marilyn Denis Show on CTV. Have a beauty question? E-mail firstname.lastname@example.org.