About a year ago, I had dyed my hair with the Splat Midnight Indigo hair dye (the one where you don't need to bleach your hair, cuz it's made for brunettes) and I was looking for other options that wouldn't stain my skin, clothes, and pretty much everything else.
My sister had been using Overtone for her hair (that had also been originally dyed with splat) and I decided to give it a try. I wanted to buy the Extreme Blue, but it was all sold out so I decided to take a chance on the Vibrant blue (conditioner and deep treatment), and it just isn't pigmented enough for my hair. The color of my hair is naturally a dirty blonde/light brown, but, even after the midnight indigo color has faded a lot, it's still much darker, and the Vibrant Blue turned it into a weird shade that definitely isn't the blue that I wanted or previously had. It wasn't even enough for my dirty blonde roots that had started to grow out. Honestly, I don't think it dyed them at all.
I will give the Extreme blue a chance, but, unless your hair is super light, I don't think the Vibrant blue is gonna do much for you, especially if your hair situation is similar to mine.
It does smell amazing and made my hair very soft, though, so A+ for that.
The picture where my hair is straight is what my hair looked like after using Overtone for a couple weeks, and the one where my hair is curled is what my hair looks like after I've just used Splat.