Semi-permanent hair color sits on the outside of the hair and usually fades faster, while demi-permanent hair color penetrates a little deeper and lasts longer. Demi-permanent also tends to blend gray hair better, while semi- permanent is the gentler, more temporary option.

Quick Scoop

Feature| Semi-permanent| Demi-permanent
---|---|---
How it works| Coats the surface of the hair 37| Deposits color a bit deeper into the hair shaft with low peroxide 39
Longevity| Usually around 8 to 20 washes, depending on the brand and hair type 35| Usually around 12 to 28 washes 139
Gray coverage| Very limited, not ideal for full gray coverage 57| Better for blending grays 39
Lightening| Does not lighten hair 37| Can subtly change tone, but still does not lighten like permanent dye 39
Damage level| Very gentle, often described as non-damaging 3| Still gentle, but uses a small amount of peroxide 13

Which to choose

  • Pick semi-permanent if you want a short-term color change, bold tone refresh, or the least commitment.
  • Pick demi-permanent if you want color that lasts longer, looks more blended, and helps with gray coverage.

Simple rule

If you want faster fade and less commitment , go semi-permanent. If you want longer wear and better blending , go demi-permanent.

If you want, I can also turn this into a shorter salon-friendly version or a more detailed comparison with examples of when to use each one.