Kustom Kolors Thinner and Base

I bought the boxset of pearlescent paints in a walmart when I was on holiday, however, now I'm back in the UK, I realise they are not prethined, and so was wondering what alternative thinner is available in the UK? Also, what colour base coat should I use for the purple passion, as it comes out nowhere near the colour it should when painted over black like shown.

Thanks

Lacquer Thinner is what I use to thin the Kustom Kolors line. Just do a 1:2 ratio and u should be fine. You could try a white base to make the purple stand out better. Good Luck