Xournal++ has basic support for changing the color palette used for the pen and highlighter tools via a configuration file. GUI support for palette customization will be implemented in the future.
Two methods for palette customization are currently available, as explained below.
Toolbar Color Tool Customization¶
In this method, the color palette is set up by manually editing the Color Tools in in your toolbar configuration.
- In Xournal++, make sure you are using a custom toolbar configuration. If you
aren't, you can create a new toolbar configuration using the menu item
View > Toolbars > Manage.
- Using a text editor, open the
toolbar.inifile contained in the Xournal++ config folder. See File locations for the location of this folder on your operating system.
- Find the section corresponding to your toolbar configuration, e.g.
- Each line under this section header defines the tools used in each toolbar.
COLOR(0x??????)items on each line. The six question marks correspond to a color in RGB hexadecimal format. Replace these hexadecimal numbers with your desired colors. To find the right numbers, you can use an online hex RGB color picker tool such as this one.
Toolbar Palette Files¶
This feature is only available on Xournal++ nightly builds.
In this method, the color palette is set up by editing a GIMP color palette file.
The palette will be loaded from a file named
palette.gpl contained in the
config folder. On the first run, Xournal++ will create
this file for you with the default color palette. Thus, the easiest way to get
started is to adjust this default file.
- Edit the
palette.gplfile located in the config folder.
- Restart Xournal++
.gpl File Format¶
.gpl file format is not authoritatively defined anywhere, so the file
format described below may be specific to Xournal++. However, Xournal++
tries to be compatible with
.gpl files used with other software such as
GIMP. If you find a
.gpl file that works in other software but does not
work with Xournal++, please file a bug report.
As an example, the default color palette of Xournal++ is shown below.
GIMP Palette Name: Xournal Default Palette # 0 0 0 Black 0 128 0 Green 0 192 255 Light Blue 0 255 0 Light Green 51 51 204 Blue 128 128 128 Gray 255 0 0 Red 255 0 255 Magenta 255 128 0 Orange 255 255 0 Yellow 255 255 255 White
If no existing
palette.gpl is found,
palette.gpl will be created with the
The palette file consists of several parts:
- Header: every palette file must begin with the line
GIMP Palette, otherwise the file will not be a valid
- A list of attributes of the form
Key: Value, one per line. These attributes are metadata that describe the palette.
- Lines beginning with
#are comments, which are ignored by the file parser. The comment used above is to distinguish the attributes from the colors of the palette.
- The colors of the palette, one per line, in the format
RRR GGG BBB Name. The
BBBcorrespond to the RGB format of the color, specified as base-10 integers in the range
0-255. To find the right numbers, you can use an online RGB color picker tool such as this one.
It's recommended to have at least 11 colors in a palette, as the default toolbar has 11 Color Items. If your palette has fewer colors, a warning will be displayed in the console, and the extra Color Items will cycle through the palette.
If Xournal++ cannot parse the palette file (i.e., the palette file is invalid), it will load the default palette. If this happens, there are two ways to get your palette file to load.
Option 1: Debugging: run
xournalpp from the command line and check for an
error message explaining why the palette file is invalid. Then, fix your
palette.gpl file, restart Xournal++, and check if the palette loaded
correctly. If not, repeat this debugging step.
Option 2: Fresh Start: delete
palette.gpl, restart Xournal++ to create
a new default
palette.gpl file, and edit again.
Creating your own palette¶
- Find RGB values to use in palettes with the MDN color picker
- Use a palette editor such as Gpick to create a
Reusing existing palettes¶
- "The Lospec Palette List is a database of
palettes for pixel art" (directly quoted from their website). Palettes can be
- You can reuse
.gplfiles from other software compatible with
.gplpalettes, such as Krita, Inkscape, or GIMP. For example, Linux users may be able to find existing palettes in locations such as