Demi-permanent color is a longer lasting alternative for men and women who want the benefits of semi-permanent color like enhancing tone and blending away gray. You can also brighten your hair _ level lighter than your regular shade with demi-permanent color. Color Duration: 6 - 20 shampoos
Ingredients: little or no peroxide, little or no ammonia
Time in Salon: 1.5 hours
Hair Penetration: deposits between cuticle and cortex
Frequency of Application: touch up re-growth every 4-6 weeks
Hey LL! I use Color by RC which is considered demi-permanent to permanent. It lasts me a couple of months before fading a little. I don't usually notice much fading because of shampoos (and I sometimes us sulfates! ) but I mostly see when my roots grow out because I have gray. Unless you are going several shades darker, you should not have a bad line of demarcation. With lowlights, you might notice a little, but how much darker are you doing the lowlights? I would think it would be similar to highlights that grow out.
SF Bay Area, CA * "The Angel-Goddess-Guru of Haircoloring" 3b/c/a mix. medium texture, low porosity
* pw: just4curlies * My Motto: Strand Test! some hair pics -- gone, but never forgotten.
How long will a demi-perm lowlight foil last in the hair with a once-weekly non-sulfate 'daily' shampoo & a once to twice monthly non-sulfate clarifying shampoo?
As well as avoiding SLS, also avoid glycerin (in conditioners, as well as shampoos, if you are able to find one without it). Glycerin grabs onto the demi-permanent pigment and makes it wash out faster.
And don't put a clear glaze that you have to mix on top of your demi! I made that mistake once with Clairol Herbal Essences Shine Happy Clear Glaze (hoping to protect the color and add shine) and it COMPLETELY stripped all the demi-permanent color out of my hair.
If you are wondering, I use Redken Shades EQ. It's waaay better than Natural Instincts. You can get it on eBay.