I am getting older and my mark-I eyeballs dynamic range is decreasing. While I can adjust gamma (xgamma -gamma 0.4) and LCD brightness, GIMP's histogram display is very dim and difficult to see.

(GIMP 2.10.18)

What I see:

low-contrast histogram

What I would prefer to see:

high-contrast histogram

Any suggestions ?

  • 1
    Hi. Welcome to GDSE. You can try some of the other themes available in GIMP. Or perhaps go find some other higher contrast themes to use. I found some here. The darker one is quite high contrast. It works in GIMP 2.10, I just tested it.
    – Billy Kerr
    Commented Apr 19, 2021 at 19:35

2 Answers 2


Thanks @Billy Kerr, all I had to do was -> Edit -> Preferences [ Interface ] / [Theme ] - Dark - Gray - Light - System <<==== double-click

Lo ! visibility 8)



As far as I can tell, in the Dark theme, the histogram in Curves uses the color noted Clr9 in the theme's gtkrc file (#454545), which is painted with partial opacity over the background that uses ClrA (#303030), so there isn't much difference:

enter image description here

So to increase the contrast you have to increase the difference between these two, with the constraints that they are used for other things. For instance setting Clr9 to #606060:

enter image description here

(as you can see this also changes the general dialog background)

To do this the simplest way is to:

  1. Locate the standard Dark theme and the location of your own private themes: Edit ➤ Preferences ➤ Folders ➤ Themes lists two folders:

    • one where you installed Gimp (in /usr/share on Linux, in C:/Program Files on Windows) for the standard themes
    • one in your own user directory (~/.config/GIMP/2.10 on Linux, C:/Users/{yourid}/AppData/Roaming/Gimp in Windows (from memory)) for your private themes.
  2. Copy the whole "Dark" theme directory to your private themes (change the name)

  3. Edit the gtkrc file with a text editor and change color["clr9"] = "#454545" (around line 79) to color["clr9"] = "#606060"

  4. Restart Gimp

  5. Change the theme to your personal theme

  6. If necessary you can change the value in the gtkrc file and update the Gimp UI instantly by clicking the Reload current theme button in the theme selection preferences page.

If you use other themes the procedure is about the same, but unfortunately the color names aren't the same in other themes. IMHO the best way to find the relevant color definition is to alter all of them to give them some color bias so that you can more easily figure out which color is used where.

  • yes thanks I did poke at these things a bit but your above insight wasn't immediately obvious :)
    – jmullee
    Commented Apr 21, 2021 at 9:52
  • I had to poke quite a bit too... :)
    – xenoid
    Commented Apr 21, 2021 at 9:56

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