I really love to experiment with my hair and the best way to do that is to use semi-permanent hair dyes in loads of crazy colours. A few months or so ago I got rid of my lovely pink hair to rock Bleach London's Washed Up Mermaid. I'd heard so many amazing, rave reviews about Bleach products and when I saw it on sale in Boots for £3 I just had to snap it up.
First things first has to be the smell of this dye. It's insane how nice this smells and it's something I'm not used to when dying my hair. Usually you get that horrible bleachy, ammonia smell but with this it sort of smells like billions of flowers are bursting and opening on top of your head. It's such a nice change and I found applying the actual dye such a pleasurable experience because of the smell. The colour of the dye actually looks a lot darker in the bottle than it is when fully applied and washed off. The blue turns into more of a sea-green colour which I guess is why they named it after mermaids (although when I think of mermaids I think of red hair....Disney problems.)
You only have to leave this dye on for around 15 minutes to get a strong colour that initially looks absolutely gorgeous. I honestly couldn't fault it at all and for the first four or five washes I was amazed at its staying power and the strength of the colour. It was around the sixth wash mark when I realised the dye was finally starting to fade but to my absolute dismay it faded to a light puke green colour, a colour which after thousands of washes just wouldn't budge. It was a colour that I hated so, so much.
I tried everything I possibly could to get rid of the horrible faded puke green colour but nothing worked. Not even bleaching over it made it disappear and that's when I realised that this hair dye had completely stained my hair. I was mortified and two months after applying it the colour was still very visible.
Thankfully the internet saved my life and I found out that by dying over the colour with a pink or a red would make the green go, so now I am actually back to having pink hair. Not by choice.
I think if you don't mind your hair being potentially stained forever and ever then this is a lovely dye. The colour at first is amazing and it lasts for such a long time. The downside to this is that you might have to dye your hair this colour until the end of time (or you know, just have more patience than me).