I started piano lessons for the 3rd time in my life after a pause of many years, so did not start from 0. However, I forgot the notes meanwhile, so labeling the piano keys made it easier to catch up with everything else, and it enables to learn they notes without doing specific targeted exercises to aim that.
The colours are also very good (blue lower octave, red higher octave) and helpful for the learning process.
You might be tempted to say: they're just a bunch of stickers, but such a small investment can make a huge difference.
I am coming from a country where the usual notation is solmization ("Do, Re, Mi...") rather than "C, D, A...", so I found it odd that most stickers for labeling piano keys are English/Deutsch notation (C, D,...). This was one downside, that the options for solization labels were quite narrow.