I bought this to cover my roots between hair color appointments. The product comes in several different colors, and is bottled like a mascara tube: you use a mascara-type brush to cover roots with a color that sticks to the hair shaft.
The medium blonde color was a good match for my base color and highlights
Since the brush is small, it's possible to add color in specific places.
The brush is poorly designed and the container has a too-tight bottle top: too much of the product is removed from the outside bristles as the brush is pulled out of the bottle so instead of sliding the brush through my hair, I have to wiggle the brush in my hair in order to get the color deposit--which often results in a "glop" of color being deposited or causes the brush to be caught in my hair. The product itself is sticky and stiff and doesn't seem to last long. I've used several bottles over the past year and sometimes the product is far too thick--which might have to do with the age of the product.
This isn't made for covering large sections of hair, either.
Summary: I use this when I'm desperate and only need a small amount of coverage. It'd be a much better product if they fixed the brush bristles and the consistency of the product.