Columbia University has released the first published study evidencing “natural re-pigmentation.” Put away the hair dye: This means hair can regain its color.

Researchers identified 323 proteins that indicate hair color. Then, they selected gray and colored hairs from 14 participants who ranked the stress in their life.

While we already know stress can cause hair to gray, this study suggests the reverse is true. Relaxing or de-stressing events can bring color back to hair even after the strands turn gray.