I have to say I liked these files and disagree with the other reviews. The colour comes off just on the first swipe, after that I didn't experience any issues. The rough side is perfect for a good file and then to follow up with the smooth side, also seemed ideal. I love the fact the colour is bright so I don't have to dig around in the bottom of the bag for ages, and the little case - genius. Nice and sturdy, I would buy again.
Not very effective, nothing like as good as professional files for a similar price, and if you have even the slightest bit of moisture under your nails the colour transfers to your skin. The plastic case is a nice touch if you want something for travel, but the files themselves are rubbish.