How to customise VS Code colours for all light (or all dark) themes?

Question

Visual Studio Code defines default colours for light and dark themes, such as

export const editorLineHighlightBorder = registerColor('editor.lineHighlightBorder', { dark: '#282828', light: '#eeeeee', hcDark: '#f38518', hcLight: contrastBorder }, nls.localize('lineHighlightBorderBox', 'Background color for the border around the line at the cursor position.'));

https://code.visualstudio.com/docs/getstarted/themes#_customizing-a-color-theme gives an example how to override a colour for particular Visual Studio Code themes

"workbench.colorCustomizations": {
    "[Abyss][Red]": {
        "activityBar.background": "#ff0000"
    },
    "[Monokai*]": {
        "activityBar.background": "#ff0000"
    }
}

How can I customise the colour for all light themes?

Answer 1

This is not directly supported at the time of this writing. It was raised before as a feature-request, but the issue ticket is now closed and locked for unstated reasons. See [themes] Support separate Dark, Light, HighContrast color theme customizations (i.e. specific to ColorThemeKind) #101418. If you have the guts, you can try raising a new issue ticket re-asking for it, and asking why #101418 got closed and locked / asking for it to be re-opened.

However, there is a workaround that might be sufficient for most use-cases. You can use [*Light*] to match themes whose names contain "Light" in them, and [*Dark*] to match themes whose names contain "Dark" in them.

For your reference / learning purposes, I found that issue ticket by googling "github vscode issues "feature-request" color customization for all light or dark themes".