So, in summary:
Formula: jelly-like (not gelly-like) - a little difficult to paint on smoothly, flakes need quite a bit of arrangement.
Flakes: pretty colours! A variety of shapes and sizes, a mixture of colours in each Splash.
Colours: Red Sea looks fine without a coloured base, but all the others really need some sort of colour underneath them as they're so translucent. My recommendation for a base colour is definitely black because it shows up the colours of the flakes best.
And here are the photos (click them to link to the swatch post):
Do you like the look of the Splash collection? Will you be heading to the Models Own Bottleshop at Westfield or their website to pick some up? On the website they're £20 for the collection with free p&p, at the Bottleshop you can pick up six polishes for £20.