Setting Desktop ThemesTelegram Support
1: First, you need to find a theme file that you like. This telegram channel has many themes already.
2: Click on any .tdesktop-theme and click "Apply this Theme" at the bottom right.
3: If you like the theme, click "Keep Changes" within 15 seconds.
To contact Telegram support, go to Settings, and scroll down until you see the 'Ask a Question' button at the bottom.
If you want to join us, check out the Telegram Support Initiative.