VSCode: TextMate Regex in User Settings

I'm trying to alter a theme to be more suitable for my daily use but I'm having some trouble trying to customize a specific word or pattern.

I'm using this format at the moment;

"editor.tokenColorCustomizations": {
    "textMateRules": [
        {
            "scope": "comment",
            "settings": {
                "foreground": "#ff0000",
            }
        },
    ]
}

Is it possible to format specific keywords or patterns?