Demi-permanent hair color is ammonia-free, slightly alters hair tone, and lasts between five to 12 washes. Unlike semi-permanent dye, demi-permanent color penetrates the first layer of hair, providing ...
Semi-permanent hair dye is exactly what it sounds like: It’s hair dye that lasts longer than temporary color, but shorter than permanent hair color. Makes sense, right? It's sort of like paint for ...