The app includes numerous customization options that you won't find with the stock messaging app, including custom contact colors, text bubble styles, and notification icons - Textra

Textra is an excellent alternative to Messages on Android. 

The app includes numerous customization options that you won't find with the stock messaging app, including custom contact colors, text bubble styles, and notification icons. 

Additionally, you get extra features such as text scheduling, the ability to blacklist contacts, and the option to rename group conversations. Textra also has excellent light and dark modes.