Here's why:
* Hair Growth Happens at the Root: Hair growth originates from the hair follicles beneath the scalp. Coloring the *shaft* of the hair (the part you see) has no impact on the processes happening at the root.
* Washable Markers are Superficial: Washable markers deposit color on the surface of the hair shaft. They don't penetrate deep enough to affect the hair follicle. Even if they did, the ingredients are not designed to interfere with hair growth.
So, while using washable markers on your hair might temporarily change its color and potentially make it feel a bit different (depending on the marker), it won't stop or slow down hair growth.