These options control the look and feel of darktable.
Set the language of the user interface. the system default is marked with an * (needs a restart).
Set the theme for the user interface.
Select this option to use the font size defined by your system. If unchecked, you may enter a custom font size in the box below (default on).
If the “use system font size” option is switched off, enter a font size (in points) for darktable to use. The font size will be changed immediately.
If performance mode is switched on, thumbnails and previews are rendered at lower quality but 4 times faster. Use this while working on a slower computer.
Adjust the global GUI resolution to rescale controls, buttons, labels, etc. Increase for a magnified GUI, decrease to fit more content in window. Set to -1 to use the system-defined global resolution. Default is 96 DPI on most systems. This needs a restart to apply changes.
Allow to apply tweaks added in text box below or not on selected theme in theme setting above.
In addition to selecting a pre-built theme to apply to darktable as a whole (above) you can also enter additional CSS customisations of your own to tweak the look-and-feel of darktable. A text entry box is provided for this purpose. You can just take what you want to change from default CSS files.
For example, if you want to change main text color, let's say to apply a pure white color, just copy/paste line 76 from darktable.css to define a @grey_100 which is a pure white color set in same css file. That way, you will have that line in CSS editor:
@define-color fg_color @grey_100;
When you have finished entering your CSS tweaks, click on the ‘save and apply’ button, which will save the tweaks to a file ($HOME/.config/darktable/user.css) and immediately apply them to the current darktable session.
If there are any issues with the entered tweaks, you can uncheck the “modify selected theme with CSS tweaks below” check box. This will immediately restore the base theme but will leave your tweaks in the editor so that you can edit and try again. Simply press “save and apply” again when you are ready to retry. This will automatically re-check the “modify selected theme with CSS tweaks below” checkbox and apply the new CSS.
If you have any issues with darktable please retry with this option unchecked to be certain that they were not caused by any of your changes.