This was a little trickier. The given cipher, cmenfyzgsvtfzyngsvaemc, was a difficult one to crack, so the hint here was very helpful. By performing some simple maths, as directed by the hint, it was revealed that every letter in the provided instruction needed to be replaced by the one before it in the alphabet. The correct input could be found by using a site such as CyberChef and solving the rotation cipher using a value of either -1 or 25 to it, you’d get the following input:

bldmexyfruseyxmfruzdlb

Once you open the link to the Rubik’s cube website and type the code above into the website, the Rubik’s cube rotates in the corresponding directions due to the inputs entered. Once you have applied these moves, the colours that make up the top corner (nearest to the camera) are YELLOW_GREEN_RED. This is the answer to the question.