Problem description

Most of the time my workflow consists in a black window (terminal or text-editor) and a white one (web browser), so any brightness level is either too dim for the dark windows or too shiny for the browser, thus effectively I have to repeatedly

  • lower brightness when going from terminal → browser.
  • increase brightness when going from browser → terminal.

Clearly this is very frustrating.

Failed attempts

I have Redshift running but it does not eliminate the problem.

Using browser extensions to darken webpages turns out not to be an option since many webpages become unreadable.

I have only one monitor, so I cannot keep dark windows in monitor X and bright ones in monitor Y.

Similar question on Ask Ubuntu but no response.



The software would automatically detect if the window is bright or dark and adjust its brightness accordingly, so that it could even deal with a split screen with one bright and one dark window.


  • The software would operate on individual workspaces, so that I could set higher brightness on a workspace where only dark windows would be spawned; or

  • The software would scale the RGB components of each screen pixel by a fixed factor, say 0.7. So #000000 (black) would still be black, #3B3B3B (gray) would be mildly darkened to #292929 and #FFFFFF (white) would be harshly darkened to #B2B2B2; or

  • Something similar.

  • 1
    I never used such, but the term for your search is "adaptable brightness" or "adaptive brightness". Just tried a search, and Gammy sounds to meet your requirements: you can set a "check-interval" so it takes screenshots every X seconds and then automatically adjusts brightness based on your settings. Homepage seems to be here. AskUbuntu also mentions wildguppy for this purpose.
    – Izzy
    May 20, 2021 at 7:04

2 Answers 2


I can recommend both Gammy and Gummy. Each app is by the same author and is open-source. Gammy is cross-platform (Linux, FreeBSD, Windows), whereas Gummy only works in Linux X11 environments.

Gammy is currently not being worked on by the original author, but I find it still works very well.

Each app will automatically adjust screen brightness, contrast, and gamma according to what is currently displayed on the screen.

The apps, including their source code, are freely available here:


Don't have the reputation to comment.

Using browser extensions to darken webpages turns out not to be an option since many webpages become unreadable.

What about the other way? Use light themes on terminals and text editors.

The Dark Reader extension for Chrome can be customized to set a different color scheme by domain I believe.


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