You may have heard gray strands take longer to absorb hair dye. But how long do you really need to leave color on to cover grays?
The processing time can vary quite a bit depending on the percentage of grays you have and your desired shade.
In general, gray hair tends to be coarse and stubborn, so leaving color on a bit longer allows the cuticle time to open so pigment can fully deposit inside the strand.
This article will provide some tips and guidelines for leaving hair color on for the right amount of time to cover gray hair and roots.
How Long to Leave Hair Dye in for Gray Hair
How long you need to leave hair dye in for gray hair will depend on the dye you’re using. Usually, you’ll need to let the dye sit for 20 to 45 minutes for gray hair.
Permanent Dye
Permanent hair dye is usually ammonia-based and can be left in your hair for up to 45 minutes. This dyeing technique will maintain your hair’s color the longest, but it does have some side effects.
If your hair isn’t adequately nourished before undergoing coloring, it can dry your hair and leave it looking dull and brittle. Also, always pay attention to your dye-specific instructions.
Semi-permanent
Semi-permanent hair dye won’t stay as long in your hair because it doesn’t have the ammonia to assist with the process. Instead of penetrating your hair, it sits on the shaft and deposits color.
The process isn’t as harsh as a permanent dye, which is nice, and it can stay for up to 20 minutes safely in your hair.
Demi-Permanent
A demi-permanent hair dye doesn’t contain ammonia but does use a developer to help the color deposit into your hair. The process won’t be as harsh as a permanent dye, but it’s not as gentle as a semi-permanent option.
You can leave this dye in your hair for up to 30 minutes.
How Long to Leave Hair Dye on Gray Roots
Natural gray hair roots are notoriously tricky when it comes to coloring.
If you’re touching up the dye, start with your roots. Give this section 20 minutes to process before you refresh the rest of your hair.
If you’re doing a full-color transformation, leave the dye on your roots for 10 minutes before working with your ends.
Pay Attention to Tough Patches
If you notice more gray in certain areas, you may also find it harder to get the dye to stick in those spots.
One way to prevent this is to apply the dye to the tough patches first. This method gives the color extra time to penetrate the hair.
When using this method, be careful to avoid an uneven dye job by thoroughly coating all the hair you want to color. Alternatively, a professional stylist can help you achieve a natural, full-bodied color.
Pay Attention to Tough Patches
If you notice more gray in certain areas, you may also find it harder to get the dye to stick in those spots.
One way to prevent this is to apply the dye to the tough patches first. This method gives the color extra time to penetrate the hair.
When using this method, be careful to avoid an uneven dye job by thoroughly coating all the hair you want to color. Alternatively, a professional stylist can help you achieve a natural, full-bodied color.
Summary
The duration for which you should leave hair dye in for gray hair varies depending on the type of dye used. The time to leave hair dye in for gray hair is as follows:
- 45 minutes for permanent dye
- 20 minutes for semi-permanent dye
- 30 minutes for demi-permanent dye
For tougher gray patches, applying dye to these areas first can help ensure more even coverage.
When touching up gray roots, a 20-minute wait time is ideal for root touch-ups, while a full-color transformation requires a 10-minute initial application on the roots before proceeding to the ends.
Frequently Asked Questions
We’ve done our best to round up some additional questions you may have:
Gray hair has a different texture from the rest of your hair and may resist hair dye, requiring more time.
Soft, neutral colors work best on gray hair.
You can risk damaging your hair by drying it out and leaving it vulnerable to breakage.