Today I have a comparison for you! I swatched four of my Nfu.Oh colours on my swatchwheel. On the left you can see the colour with three coats, and on the right you can see 2 coats of black polish and one coat of the Nfu.Oh colour!
51:
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Slightly darker purple in real life. As you can see, the colour really changes with black polish underneath. From a purple kind off colour, to a redish colour.
52:
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There's is more green on the right side in real life, depending on the lighting. But it really changed from blue to green!
54: (Yes, this one is reversed.. so the left side has the black polish underneath)
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This polish has a clear base so you can't really see a lot of it without a colour underneath. I think this one looks very pretty with the black polish!
60: (reversed too)
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Basically it's the same. Only without the black polish, it's a litte more sheer and dull. I like it better when it's layered over black.
Thanks for reading! :)