Playlist icons in Music out of control

Any insight why Apple is assigning some playlist icons a red/white gradient? I've not been able to figure out what triggers it, and it has the very unfortunate effect of making some playlists more visually prominent. I've often dozens of playlists in a folder and want them all to have the normal default (music symbol with the three lines as you can see on the image attached) so I can quickly scan based on what I've named them, without being distracted by random red blobs. Much obliged for any help.

Music v.1.6.2.57 / MacOS Tahoe 26.2