Modify Islands Theme

Hi Phil, and thanks for contacting JetBrains support.

To achieve that, you will need to change the Editor color scheme. Could you please go to Settings | Appearance and Behavior | Appearance, and select the theme’s default option, as shown in the image below:

After doing so, the background of the Editor, Terminal, and other tool windows should correctly match the selected theme.

Thanks for the reply Petar

I want to manually set the background colour of the tool windows.

The main editor is done from Settings > Editor > Color Scheme > General > Text > Default Text > Background

The terminal is Settings > Editor > Color Scheme > Console Colors > Reworked Terminal > Default Background

The project window used to work from Settings > Appearance & Behaviour > File Colours > + to add new, all, pick colour, move to bottom of order. This no longer updates the full background of the window, shown in my screenshot, it leaves the default gray for areas where there are no files. 

I would also like a way to customise terminal tab background and file tab backgrounds, outside of changing the theme. (Editing the overall interface theme)

Hi Phil, got it, sorry I thought you wanted to use the theme’s default colors across all tool windows.

I am afraid the exact functionality you are looking for is not supported, but I found two workarounds:

1. Setting a solid-color background image. Please make sure you are on version 2025.3, as earlier versions had a bug where background images were not displayed correctly when using the new Islands themes (see IJPL-192439).
2. If you want more detailed theme customization, such as applying different colors to specific UI elements, use the Theme Patcher plugin. You can read more about how it works here. The keys you will likely want to modify are ToolWindow.background and EditorTabs.underlinedTabBackground. You can find other keys by using the UI Inspector.

edit: I recommend enabling Color Key Picker in the UI Inspector; it makes finding keys much easier.