Dark theme for Ubuntu

mikedb · November 21, 2025, 6:26am

Hi Everyone.
Arduino 1.8.19

In the file path /Arduino 1.8.19 / lib / theme / syntax /
there is two themes "Default.xml" and "Dark.xml" but I cannot select "Dark" in the Arduino preferences.

The options I Googled so far is to download the Dark theme from Github but it is already installed.

I did rename "Default" to "Default1" and "Dark" to "Default" start Arduino ide , nothing to select in preferences and theme is still not Dark.

How do I change to the Dark theme?

ptillisch · November 21, 2025, 7:38am

Hi @mikedb. I think that file was the result of someone starting on creating an official dark theme for the IDE, but they never actually followed through to finish the project.

However, the Arduino community has created several themes. Maybe one of those will be to your liking. I'll share the list of all the themes I know of:

Custom Theme

If you decide you want to modify an existing theme, or make your own from scratch, you can find documentation of the theme system and a dummy library and sketch to facilitate testing here:

Installation

You have two options for installing themes to the sketchbook: direct installation or installation as "ZIP" files.

I'll provide instructions for both options below:

Direct installation

This installation option is best if you are going to use a single custom theme.

Select File > Preferences... (or Arduino > Settings... for macOS users) from the Arduino IDE menus.
The "Preferences" dialog will open.
Take note of the path shown in the "Sketchbook location" field in the "Preferences" dialog.
This is the path to your "sketchbook folder".
Click the "Cancel" button.
Select File > Quit (or Arduino > Quit Arduino for macOS users) from the Arduino IDE menus.
All Arduino IDE windows will close.
Open the sketchbook folder in your file manager.
If you are using Windows, this would be File Explorer.
Create a subfolder in your sketchbook folder named theme.
Put the theme directly into the theme folder you created.

The folder structure must look like this:

<sketchbook folder>
|_ theme
   |_ syntax
   |   |_ etc...
   |_ theme.txt
   |_ etc...

"ZIP" file installation

This installation option is best if you want to switch between multiple custom themes, or if you are using a pre-made theme that supports this installation method.
The second option is to put the theme in a "ZIP" file, then put that in the theme subfolder of the sketchbook folder.

Select File > Preferences... (or Arduino > Settings... for macOS users) from the Arduino IDE menus.
The "Preferences" dialog will open.
Take note of the path shown in the "Sketchbook location" field in the "Preferences" dialog.
This is the location of your "sketchbook folder".
Click the "Cancel" button.
Select File > Quit (or Arduino > Quit Arduino for macOS users) from the Arduino IDE menus.
Open the sketchbook folder in your file manager.
If you are using Windows, this would be File Explorer.
Create a subfolder in your sketchbook folder named theme.
Put the theme "ZIP" file directly into the theme folder you created.
Start Arduino IDE.
Select File > Preferences... (or Arduino > Settings... for macOS users) from the Arduino IDE menus.
Select the theme from the File > Preferences > Theme menu.
Select File > Quit (or Arduino > Quit Arduino for macOS users) from the Arduino IDE menus.
All Arduino IDE windows will close.
Start Arduino IDE.
The theme you selected from the menu will now be active.

The folder and "ZIP" file structure must look like this:

<sketchbook folder>
|_ theme
   |_ MyCoolTheme.zip
      |_ syntax
      |   |_ etc...
      |_ theme.txt
      |_ etc...

There is a sort of tricky thing about this installation option. The theme must be in the root of the "ZIP" file, NOT in a subfolder. Some "ZIP" utilities make that difficult or even impossible (especially the macOS one), but a Windows user won't have any difficulty:

Select all the files of the theme in Windows File Explorer.
Right click on the selected files.
Select Send to > Compressed (zipped) folder from the menu.

The awesome thing about this option is it allows you to have multiple themes installed (each in its own "ZIP" file). You can chose which one you prefer via the "Theme" menu of Arduino IDE's "Preferences" dialog. This menu will include the option to select the "Default theme", which is the one installed with the IDE.

Let's say you had two themes, one you wanted to show up in the Theme menu as "MyCoolTheme" and another you wanted to show up as "MyOtherCoolTheme", the folder structure should look like this:

<sketchbook folder>
|_ theme
   |_ MyCoolTheme.zip
   |  |_ syntax
   |  |   |_ etc...
   |  |_ theme.txt
   |  |_ etc...
   |_ MyOtherCoolTheme.zip
      |_ syntax
      |   |_ etc...
      |_ theme.txt
      |_ etc...

mikedb · November 21, 2025, 8:15am

Thanks got it to work in Windows ide 1.8.19.
I did not test it on Ubuntu yet.

I pick a theme from the middle of the list >conrad91 this is the comparison.
Can I copy the the theme from 2.3.6 to 1.8.19?

1.8.19 Left and 2.3.6 Right , need to find a theme that looks the same.

ptillisch · November 21, 2025, 8:28am

No. The two applications use completely different theming systems.

mikedb · November 21, 2025, 9:48am

Thanks.

Where is the "theme" folder in Windows for Arduino 2.3.6.
I did test a few of the themes in your list but it seem to not look the same as in 2.3.6.

So my idea is to change the colors of a theme that is almost the same as in 2.3.6 using the theme colors from 2.3.6.

ptillisch · November 21, 2025, 10:13am

For Arduino IDE 2.x, you install themes under a folder you create at the following path on your hard drive:

C:\Users\<username>\.arduinoIDE\plugins

However, that is only for additional themes you install. It appears you are using the built-in "Dark High Contrast" theme in Arduino IDE 2.x. The source of that theme is here:

github.com/eclipse-theia/theia

packages/monaco/data/monaco-themes/vscode/hc_black.json

v1.57.0

{
  "$schema": "vscode://schemas/color-theme",
  "name": "Dark High Contrast",
  "colors": {
    "editor.background": "#000000",
    "editor.foreground": "#FFFFFF",
    "editorIndentGuide.background": "#FFFFFF",
    "editorIndentGuide.activeBackground": "#FFFFFF",
    "sideBarTitle.foreground": "#FFFFFF",
    "selection.background": "#008000",
    "editor.selectionBackground": "#FFFFFF",
    "statusBarItem.remoteBackground": "#00000000",
    "ports.iconRunningProcessForeground": "#FFFFFF",
    "editorWhitespace.foreground": "#7c7c7c"
  },
  "tokenColors": [
    {
      "scope": [
        "meta.embedded",
        "source.groovy.embedded"

This file has been truncated. show original

A community member shared information on the Arduino IDE 2.x theme system here:

mikedb · November 22, 2025, 8:11am

Thanks a lot , I manage to change Ubuntu to a Dark theme.

ptillisch · November 22, 2025, 7:35pm

You are welcome. I'm glad you were able to get the theming to your liking.

Out of curiosity, which specific theme did you end up using? Did you use one of the ones the community created, or did you make your own custom theme?

mikedb · November 23, 2025, 8:02am

Way to complicated to start my own theme , I just edit the theme.

I tested a few themes and ended up with the "conrad91"theme.
I manage to change the back ground from grey to black and the comments from white to green.

Still need to make the green brighter and change the pinkish to Orange.

ptillisch · November 23, 2025, 11:20am

Very much needed. The current comment color is a bit depressing to look at against the black background!

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Dark theme for Ubuntu

Custom Theme

Installation

Direct installation

"ZIP" file installation

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