F3 and F4 are darker than my skin tone but I have applied them all to my nails so you can get an idea of the colours and coverage. Two coats gives good opaque coverage with all four foundations. I find the size and shape of both the bottle and brush easy to handle. I did experience some dragging if I had to go back over an area whilst applying a coat, so it helps to be precise first time. The RGB formula is free of formaldehyde, toluene and dibutyl phthalate (DBP), in fact I recall London Makeup Girl mentioning that they are in fact 4-free as they are also free from camphor. The polish lasted well on my (notoriously difficult) nails. I'm not sure if the fact that I used my BECCA 2-in-1 as a base coat helped with the lasting power, this is also a 4-free formula so it's probably a good match as a base coat.
I have to admit that I'm not sure whether I prefer F1 or F2 on my hands. F2 is a bit too dark to truly give the effect of mannequin hands but the undertone blends in better with my skin, whereas F1 seems to highlight the redness in my skin. F1 will probably be more flattering when my hands are less winter abused.
Although the idea of the nail foundations is for them to match your skin tone, I really like the colour of F3. In the top picture, I think it looks unfairly.....erm, dungy which is why I have included the whole hand picture to give you a better idea of the colour.
F4 is a really rich deep brown and I think it has the most glossy finish of the Nail Foundations.
As well as the Nail Foundation, there are four Nail Tints available which offer similar skin matching shades but in a sheer finish. I actually think I will get on better with these for finding my perfect skin match and I always thing that sheer fleshy colours are a good choice if you struggle to keep a manicure looking perfect.
The HIPP x RGB Nail Foundations cost £11.50 each and are available from Mise Beauty, who ship worldwide.
Disclosure: These items were sent to me without cost for review purposes.