PXP Professional Colours, PaintGlow and Superstar Neon UV Face Paint
Here is an option to shop for face paints by Neon UV colour. Scroll down or pick a colour from the list to see all Neon UV colours choices in different sizes.
Neon UV Face Paint from 10g are small enough so that you can try out colours with out having to buy too much facepaint. Large single colours are for when you need a lot of one colour.