This is a custom copy of the ui-darkside theme from Mailspring, created for my personal use.

Below is the documenation of original theme

Darkside

An dark sidebar theme for Mailspring. Created by Jamie Wilson

Customize

Open the theme directory
If you're on a Mac, you can find the theme files at /Library/Application Support/Mailspring/packages. To get there quickly, use the key command Cmd + Shift + G and enter /Library/Application Support/Mailspring/packages.

Change package.json
In order to avoid conflicts between your custom theme and the pre-installed version, change name and displayName in package.json to:

"name": "ui-darkside-custom",
"displayName": "Darkside Custom",

Edit LESS files
Open the ui-variables.less file. To change colors, just comment out the default @sidebar and @accent variables and uncomment another theme or simply replace with your own colors.

// Default
@sidebar: #313042;
@accent: #F18260;

// Luna
// @sidebar: #202C46;
// @accent: #39DFF8;

// Zond
// @sidebar: #333333;
// @accent: #F6D49C;

// Gemini
// @sidebar: #00203C;
// @accent: #F6B312;

// Mercury
// @sidebar: #555;
// @accent: #999;

// Apollo
// @sidebar: #3A1E15;
// @accent: #F6AA1C;

Feedback

If you have questions or suggestions, please submit an issue. If you need to, you can email me at [jamie@jamiewilson.io](mailto:jamie@jamiewilson?subject=Re: Darkside).