Here’s some hopeful news for anyone staring at a few too many gray strands in the mirror: scientists say gray hair may not be a permanent fate after all. In a fascinating new study researchers found that graying could come down to certain pigment stem cells getting stuck in the wrong place inside hair follicles—and that moving them again might restore color.

The study focused on special cells called melanocyte stem cells (McSCs). Normally, these cells are pretty amazing. They bounce back and forth inside hair follicles, shifting between different compartments that help them stay flexible and able to turn into pigment-producing cells. This dance is what keeps hair colored as it grows. But researchers discovered that over time, or with age, many of these cells get trapped in a spot called the follicle bulge. Once stuck there, they can’t make their usual trips to the germ compartment, which means they stop picking up the signals (like WNT proteins) needed to turn into pigment cells. The result? Gray hair.

In mice, scientists saw that follicles with these “jammed” stem cells often lost color, while follicles where McSCs stayed mobile kept making pigment. This gives hope that if we can figure out how to unstick these cells, or keep them moving, we might actually be able to reverse gray hair. The researchers believe this same mechanism probably happens in humans too. So future treatments could target these pigment cells to keep hair looking youthful.