Customize block quote color in VSCode theme

Question

I am using Nord theme in VScode. The block quotes in the markdown files look like this which is very illegible. How to change the text background?

I have tried the followings in User Settings but it not working:

"workbench.colorCustomizations": {
    "textBlockQuote.background": "#ff0000", // changes the markdown preview
    "editor.textBlockQuote.background": "#0000ff", // Property not allowed
    "[Nord]": {
        "textBlockQuote.background": "#ff0000", // changes the markdown preview
    },
},
"editor.tokenColorCustomizations": {
    "textBlockQuote.background": "#ff0000", // Property not allowed
    "editor.textBlockQuote.background": "#ff0000", // Property not allowed
    "[Nord]": {
        "textBlockQuote.background": "#ff0000", // Property not allowed 
        "editor.textBlockQuote.background": "#ff0000", // Property not allowed
    }
},

Answer 1

The editor colorization comes from a textmate grammar. To override this, you need to use the textMateRules section of editor.tokenColorCustomizations

"editor.tokenColorCustomizations": {
    "[Nord]": {
        "textMateRules": [
            {
                "scope": "markup.quote.markdown",
                "settings": {
                    "foreground": "#f0f"
                }
            }
        ]
    }
}

The scope used here (markup.quote.markdown) is the textmate scope of markdown block quotes. You can use the Developer: Inspect TM Scopes command in VS Code to determine the target scope

Note that VS Code does not support setting the background color of text. This is tracked here

Answer 2

I use Slack Theme Aubergine Dark and had to change:

   "editor.tokenColorCustomizations": {
        "[Slack Theme Aubergine Dark]": {
            "comments": "#ffa600",
            "textMateRules": [
                {
                    "scope":"markup.quote.markdown",
                    "settings": {
                        "foreground": "#FF0000",
                        "fontStyle": "bold"
                    }
                }
            ]

        },

    },