On reflection, I realised that I'm being a bit hard on myself - this didn't call for an exact replica of an artwork, it called for arty inspiration. So, I stuck with my original plan and went for Starry Night.
I just picked a couple of blues and purples, a white and a gold - and this is what I came up with.
Here's an indoor/outdoor comparison:
I like it, it's one of my favourite colour combinations so far. I didn't have any particular method for this one - just used a blue polish as a base coat (Catrice LE Miracle Heaven) and splattered some random polishes all over it. What do you think?