Splat Midnight

As far as I can see, they're nothing special.

It says that the lighter your hair colour, the brighter the colour will look. It's just darker dyes, maybe with extra pigments (good chance they'll rub off over everything too!), which will act the same as any other darker direct dye.

I still can't imagine someone with dark red hair getting a good result with a blue dye though. Best result would be a muddy purple, not a great result if you're expecting navy.

What I find most hilarious though, ALL of the articles I just looked at (6) had a pale, or at least definitely bleached before, colour as the picture! Not one single article had an example of the dye that they're talking about.