Colors are not accurate in Telegram

I'm using Catppuccin in many applications, but in Telegram Desktop on MacOS (installed viac App Store) the colors are not accurate. See the screenshot, this should be Catppuccin Mocha, the background should be much darker, not greyed out like this. Any ideas what could be the issue?

Reproduce the issue in Telegram Desktop on macOS using the App Store installation and compare the result with the attached screenshot. Since no file, test, or entry point is named, first locate the Catppuccin Mocha theme assets in this repository and determine why the background appears grey rather than dark; done means the Telegram colors match the theme.

Written by the indexing model from the issue text.