textDecoration可以有比underline更多的选项，它可以直接包含下划线的颜色-所以下面的代码将创建一个蓝色下划线，而不需要对所有文本进行着色（color选项适用于所有文本）：

const blueMarkToggleType = vscode.window.createTextEditorDecorationType({
    isWholeLine: false, // apply the text decoration only to the marked characters
    textDecoration: "underline #ff0000", // solid, dark blue line under the text
    // color: "#0000FF", // solid, dark blue color for the text decoration
    overviewRulerLane: vscode.OverviewRulerLane.Center
});

要尝试处理您选择的textDecoration颜色（我不认为这是可主题化的）在黑暗和光明主题中的显示方式，您可以通过添加dark和light选项来覆盖默认的textDecoration：

const blueMarkToggleType = vscode.window.createTextEditorDecorationType({
    isWholeLine: false, // apply the text decoration only to the marked characters
    textDecoration: "underline #ff0000", // solid, dark blue line under the text
    overviewRulerLane: vscode.OverviewRulerLane.Center,

    light: {
        textDecoration: "underline #0f0"  // green in a light theme
    },
    dark: {
        textDecoration: "underline #00f"  // blue in a dark theme
    }
});