REVIEW and GUIDE OF THEMES:
Download mat recovery theme from link given below flash it in your recovery.
Then u will get new themed mat recovery.
Now flash any recovery theme and your phone will changes to new recovery theme.
Or after reboot if you want to change theme from file explorer.
Then go to TWRP FOLDER>THEN THEME>THEN CHANGE UI. ZIP name to ui. original. Zip
Now paste any zip theme u downloaded in above folder. Rename it to ui. Zip
And then reboot
If u want to remove all themes then delete all ui.zip from your theme folder and reboot
1) mat recovery theme:
2) ALL THEMES COLLECTION
Download as oer your recovery version means 18.104.22.168 or 22.214.171.124
Bunch of themes available