I tried some of the covers here on thingiverse - those that slot into the v-slots. For them I had to disassemble the belt tensioner and both of them broke during assembly. So I deciced to create my own cover and make it a simple clip-on that you just have to print and snap on the white axle without disassembling the belt assembly. And of course I wanted the cover to look good and match the angular style of the printer.
There is one version with the Ender Logo (quite difficult to print in this small dimension) and a blank version included.
I strongly recommend printing it with 100% infill to get maximum strength, especially for the snap-on clamps