appearance.koplugin
The ultimate plugin to customize 
KOReader's appearance in any way you would like! It adds features that are similar to those found in other ebook readers like Readest, Librera, & Moon+ Reader, making it the ideal reader.
Features
| Category | What you can change |
|---|---|
| Themes | Apply full UI & book themes with one tap |
| Colors | Customize background, font, link, highlight, and progress bar colors |
| Color wheel | Choose colors with a visual RGB color wheel |
| Font | Customize your own unique UI and dictionary fonts |
| Page style | Adjust page colors for a comfortable reading experience (both reflowable & fixed-layout documents such as EPUBs, PDFs, DJVUs, & CBZs) |
| Backgrounds | Set custom background images (like a wallpaper) |
Installation
- Download the latest release.
- Extract the
appearance.koplugindirectory from the archive. - Move the
appearance.koplugindirectory to thekoreader/pluginsfolder on your device. - Restart KOReader.
Configuration
The plugin can be fully configured under the new Appearance menu on the 
Settings tab. The appearance of the User interface and Book can be configured separately as well together via Themes.
Usage
Applying a Theme
Navigate to 🞂 Appearance 🞂 Themes and select any theme from the list. The UI updates instantly without needing to restart.
To go back to the default look, choose 🞂 Appearance 🞂 Themes 🞂 Reset themes 🞂 Reset to default themes. This clears all theme overrides and restores KOReader's original colors.
Themes can also be selected automatically using dispatcher actions (e.g., via profiles or gestures).
Adding/Configuring Themes
Themes can be added by pressing 🞂 Appearance 🞂 Themes 🞂 Add a theme, from there you can choose the background and foreground colors for the theme.
Themes can be configured by holding down on them when selecting them from the list. Then, an option menu will show that gives you the ability to rename, change the colors of, and delete the theme.
Setting a Background Image
Go to 🞂 Appearance 🞂 User interface 🞂 Background image and pick an image from your device storage. The background will apply immediately across the UI.
You can select where you want the background image to be shown, such as in the file browser, reader, the top menu, and SimpleUI homescreen.
To remove it, return to the same menu and hold down on the currently selected image.
A background image can also be automatically set/changed by using the "Select background image" action in profiles. This allows you to set one of the past background images automatically or by gestures.
Changing Colors
Under 🞂 Appearance 🞂 User interface:
- Background color - the main canvas behind text and UI elements
- Font color - the color of all rendered text
Under 🞂 Appearance 🞂 Book:
- Background color - the color of the page background
- Font color - the color of the page text
- Link color - the color of the page links
- Highlight colors - the colors used when annotating (each name can also be edited)
- Progress bar colors - the read/unread colors of the book progress bar in the footer
Each color can be chosen by color picker and code. Changes apply live so you can preview as you go. There are Advanced settings as well that allow you to experiment with more fine-tuned tweaking.
Changing the UI/Dictionary Font
Go to 🞂 Appearance 🞂 User interface 🞂 Font or 🞂 Appearance 🞂 User interface 🞂 Dictionary font. From there you will see a list of the fonts found (the exact same as the ones for books), and you can select whatever font you would like.
If at any time, you would like the original look, you can toggle Enable font replacement to disable your changes.
The supported font formats are .ttf, .otf, .pfb, and .pfa.
These are the folders where you may place your fonts:
- Android/Boox:
koreader/fonts/ - PocketBook:
applications/koreader/fonts(Create the folder) - Kobo:
.adds/koreader/fonts(Create the folder) - Desktop/Linux: Install the font for the system OR
.local/share/fonts
Updating the Plugin
Go to 🞂 Appearance 🞂 About 🞂 Check for updates to fetch and install the latest release of the plugin. Restart KOReader after installing for the changes to apply.
You can also enable automatic checking for updates to be notified when new versions are released.
Compatibility
Tested fully on e-ink, desktop, and mobile devices. Fully compatible with popular plugins like Rakuyomi and SimpleUI.
PDF background color customization is compatible with the dual pages feature introduced by ComicReader by @OGKevin.
For rounded book & folder covers to work properly with the background color, my special rounded cover patches should be used.
Acknowledgements
- Features originally integrated from my KOReader patches.
- Theming functionality inspired by 2-color-theme.lua by @artemartemenko.
- The packaging system in use is based on work from ComicReader by @OGKevin.
- UI font replacement based on the patch 2--ui-font.lua by @sebdelsol.
- Dictionary font replacement based on the patch 2-custom-ui-fonts.lua by @gennaro-tedesco.
- In-plugin updater adapted from the one used in Bookends by @AndyHazz.
- Markdown implementation for Lua sourced from markdown.lua by @mpeterv and @niklasfrykholm.
Support
If you want to support me, you can star this repository or buy me a coffee. :)
License
This project is licensed under the GNU General Public License v3.0. See the LICENSE file for full details.