Oh I do love a temperature-sensitive polish! The best ones I've tried so far are the Ferity Miss Match ones, which are tiny, cute bottles with lids shaped like pencils. I believe they're a Russian (or perhaps Polish) brand, but I buy them on Amazon from a UK seller, who charges under £2.50 a go, which I think is a pretty good deal. I have been after the red one for a while, and it was finally back in stock this week!
This is Red Temptation, two coats, with topcoat.
This is a lovely bright tomato red when cold. I really like this sort of shade of red - I have a LOT of red polish in my collection!
When warm, this is a juicy yellowy orange. The colour really looks like orange juice to me!
I'm not sure I like the effect when my entire nail is hot (as you can see, there's quite a bit of visible nail line), but I love the gradient effect from hot to cold - it reminds me of a tequila sunrise!
The formual on these polishes isn't great - they smell bad, and they're quite gloopy, so they can be a bit lumpy and do tend to need Seche Vite to smooth it out. The brushes are also a bit fiddly - the pencil cap is a bit small to hold, and the brush is small. But having said all that - I LOVE these polishes. The colour change is really strong and effective, and they make me happy to sit and watch the change. And there's a huge range of colours too.
I mean, who doesn't want nails that look like a sunset?