If you spill hair dye on your carpet, it's a real nightmare. You need to start cleaning immediately, but even if the paint is absorbed, there is one secret how to remove it. There are 2 ways.
Steps

Step 1. Get out the liquid dish soap and white vinegar
Mix one tablespoon of each ingredient with 2 cups of warm water.

Step 2. Take a clean (white) cloth
Rub the stain with a sponge dipped in detergent / vinegar, blotting frequently with a dry cloth, until the stain is gone. (It may not completely disappear right away, just go to the next step.)

Step 3. Rub the stain with a sponge dipped in cold water
Blot again until all liquid is absorbed.

Step 4. Rub with a sponge dipped in rubbing alcohol
Wipe again with a dry cloth while continuing to remove the stain.

Step 5. Wipe again with a sponge soaked in cold water
The stain usually disappears, but if it still remains, try the following tips.

Step 6. Take detergent and ammonia
This time, mix 1 teaspoon of detergent and 1 tablespoon of ammonia with 2 cups of warm water.

Step 7. Rub the stain with a sponge with this solution
Leave it on for about 30 minutes, blotting every 5 minutes with a clean cloth and refilling with new solution.

Step 8. Rub with a sponge with cold water and blot with a dry cloth one last time
If all else fails, you can use another less successful method, but you can still try it.

Step 9. Find hydrogen peroxide
Use a pipette to add hydrogen peroxide to the stain and let it sit for 24 hours. Repeat as needed. Note that it is worth trying this method first on an unobtrusive part of the carpet because the peroxide can discolor your carpet.