Available in version 3.6 or later.
You can change colors of SumatraPDF UI by creating a custom theme using Themes advanced setting.
To create a theme:
Example of customization:
Themes [
    [
        Name = My Dark Theme
        TextColor = #bac9d0
        BackgroundColor = #263238
        ControlBackgroundColor = #263238
        LinkColor = #8aa3b0
        ColorizeControls = true
    ]
]
TextColor and BackgroundColor are for main window color and color of text.
If you use I (CmdInvertColors) they will also be used to replace white background / black text color when renderign PDF/ePub documents.
ControlBackgroundColor is for background of Windows controls (buttons, window frame, menus, list controls etc.).
LinkColor is a color for links. Typically it’s blue.
ColorizeControls should be true. If false we won’t try to change colors of standard windows controls (menu, toolbar, buttons etc.) so a lot of UI will not respect theme colors.

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