Review (5/5): Well worth the money and great for masking mistakes!
This product is definitely darker than I expected. My hair is a very dark brown often mistaken for black, and it's almost too dark for me to pull off. Granted, I do leave it on for 30 minutes because otherwise the color looks more green on my skin. It might just be my undertone, though, so don't let that deter you. I'm ordering the lighter brown to mix in with this color to see if it's a better match with a 1/4 ratio since it seems more red based.
If you already have thick (dense) brows and are trying to groom them back into the right shape after a mishap, this product is a great tool! It also works well with masking the scar at the top of one of my brow arches. So glad I gave it a try.