Creating Custom Themes in Helium

Overview

Helium supports fully customisable colour themes. The easiest way to create or edit a theme is with the free Helium Theme Editor - a web-based tool with a live preview that requires no technical knowledge.

Using the Theme Editor

Open the Helium Theme Editor in your browser to get started.

Start from a preset

Choose any of the 15 built-in themes from the Preset dropdown to use as a starting point. The preview panel on the right updates immediately.

Name your theme

Type a name in the Theme name field. This is the name that will appear in Helium's theme picker.

Adjust colours

The editor panel on the left is divided into four collapsible groups:

  • Surfaces - main backgrounds, sidebar, cards and the Quick Tag Editor
  • Accents - primary and secondary accent colours, and the playing-track row highlight
  • Misc - waveform tick background and light or dark base style
  • Telerik Overrides - fine-tune control colours such as hover highlights, selection backgrounds, selected text and borders

Click any colour swatch to open the colour picker. The preview panel updates in real time as you make changes. Fields with an × button are optional - click × to clear that value and fall back to the base default.

Import an existing theme

Click Import JSON to load a theme you have previously exported or received from another user. The editor reads the theme data from your clipboard.

Export your theme

When you are happy with your theme, click Export JSON. The editor copies the theme to your clipboard and downloads it as a .json file named after your theme.

Installing a Theme in Helium

  1. Move the downloaded .json file into your Themes folder: %AppData%\Imploded Software\Helium 18\Themes\
  2. In Helium, open Tools ? Options ? Visual.
  3. Click Refresh to pick up the new file.
  4. Select your theme from the dropdown.
  5. Click Preview to see how it looks before applying it.
  6. Click OK. Helium will prompt you to restart - your theme takes effect after the restart.

Built-in Themes

Helium ships with 15 built-in themes: Default Dark, Default Light, Warm Dark, Warm Light, Ayu Dark, Catppuccin Mocha, Darcula, Gruvbox, Nord, One Dark Pro, Osaka Jade, Rosé Pine, Shades of Purple, Synthwave '84 and Tokyonight. All themes are available to every user at no extra cost. Custom themes you create yourself are also free to use.

Advanced: Editing Theme Files Manually

Theme files can be opened in any text editor if you prefer not to use the web editor. Colour values are written as six-digit hex codes in the format #RRGGBB. Optional fields in the Telerik Overrides section can be cleared using the × button in the Theme Editor, which restores the base default for that colour.

After saving your edits, click Refresh in Tools > Options > Visual and restart Helium to apply the changes.

To reset a built-in theme to its original colours, delete its .json file from the Themes folder and restart Helium - the file will be recreated automatically.