There is an easy way to make them look better, though: add a diffuser. That’s what [Nate Damen] did using a 3D printer. He created a diffuser using PETG giving a standard string of LEDs a softer ...

A drop of hot glue works pretty well, because it’s rarely crystal clear ... You could always 3D print the case in a translucent material, so that the case is the diffuser.