BYS Glitter Blue is amazing! It's cheap as balls, it's a pretty baby blue with the perfect amount of silver micro glitter, it's a suede finish, and it changes colour depending on the temperature!
I bought it because it was a colour changer but that turned out to be the least interesting thing about it. I was hoping that the nail tips, being cooler, would be a different colour and give me a no fuss gradient effect but, as you can see, the whole nail stayed "hot". I eventually ran them under cold water to see the colour change and was disappointed that they only darkened by a shade or two.
The polish is quite sheer so I used four coats and you can still see the nail line, although this doesn't bother me as much as some. The suede finish is lovely and the tiny silver glitter really makes the whole thing quite delicate and gorgeous.
Four coats of colour over one coat of OPI Matte Nail Envy. No top coat.