Bienvenido al mundo de las carátulas de tu Mi Band 4
Guide to install custom Watchfaces on Xiaomi Mi Band 4 - Gizmochina
Mi Band 4 Watch Faces - Apps on Google Play
The Xiaomi Mi Band 6 Revisited - Scargill's Tech Blog
Mi Band 4 WatchFaces - Apps on Google Play
Mi Band 4 Watchfaces for Android - Download the APK from Uptodown
The only band 5 watch face that has resonated with me. It's minimal, appeals to my inner child, plus it kinda looks like a marshmallow. I linked to it in the comments.
MiBand 4 - Watchfaces - Apps on Google Play
Mi Band 4 WatchFaces - Miband4 - Apps on Google Play
Mi Band 4 Watch Faces - Apps on Google Play
Mi Band 5 Watch Faces APK for Android - Download