diff --git a/assets/js/cell/live_editor/theme.js b/assets/js/cell/live_editor/theme.js
index 2105e499d..4fd6bda2e 100644
--- a/assets/js/cell/live_editor/theme.js
+++ b/assets/js/cell/live_editor/theme.js
@@ -1,39 +1,61 @@
 // This is a port of the One Dark theme to the Monaco editor.
 
+const colors = {
+  default: "#abb2bf",
+  lightRed: "#e06c75",
+  blue: "#61afef",
+  gray: "#5c6370",
+  green: "#98c379",
+  purple: "#c678dd",
+  red: "#be5046",
+  teal: "#56b6c2",
+  peach: "#d19a66",
+};
+
 const theme = {
   base: "vs-dark",
   inherit: false,
   rules: [
-    { token: "", foreground: "#abb2bf" },
-    { token: "variable", foreground: "#e06c75" },
-    { token: "constant", foreground: "#61afef" },
-    { token: "constant.character.escape", foreground: "#61afef" },
-    { token: "comment", foreground: "#5c6370" },
-    { token: "number", foreground: "#61afef" },
-    { token: "regexp", foreground: "#e06c75" },
-    { token: "type", foreground: "#e06c75" },
-    { token: "string", foreground: "#98c379" },
-    { token: "keyword", foreground: "#c678dd" },
-    { token: "operator", foreground: "#d19a66" },
-    { token: "delimiter.bracket.embed", foreground: "#be5046" },
-    { token: "sigil", foreground: "#56b6c2" },
-    { token: "function", foreground: "#61afef" },
-    { token: "function.call", foreground: "#abb2bf" },
+    { token: "", foreground: colors.default },
+    { token: "variable", foreground: colors.lightRed },
+    { token: "constant", foreground: colors.blue },
+    { token: "constant.character.escape", foreground: colors.blue },
+    { token: "comment", foreground: colors.gray },
+    { token: "number", foreground: colors.blue },
+    { token: "regexp", foreground: colors.lightRed },
+    { token: "type", foreground: colors.lightRed },
+    { token: "string", foreground: colors.green },
+    { token: "keyword", foreground: colors.purple },
+    { token: "operator", foreground: colors.peach },
+    { token: "delimiter.bracket.embed", foreground: colors.red },
+    { token: "sigil", foreground: colors.teal },
+    { token: "function", foreground: colors.blue },
+    { token: "function.call", foreground: colors.default },
 
     // Markdown specific
     { token: "emphasis", fontStyle: "italic" },
     { token: "strong", fontStyle: "bold" },
-    { token: "keyword.md", foreground: "#e06c75" },
-    { token: "keyword.table", foreground: "#e06c75" },
-    { token: "string.link.md", foreground: "#61afef" },
-    { token: "variable.md", foreground: "#56b6c2" },
-    { token: "string.md", foreground: "#abb2bf" },
-    { token: "variable.source.md", foreground: "#abb2bf" },
+    { token: "keyword.md", foreground: colors.lightRed },
+    { token: "keyword.table", foreground: colors.lightRed },
+    { token: "string.link.md", foreground: colors.blue },
+    { token: "variable.md", foreground: colors.teal },
+    { token: "string.md", foreground: colors.default },
+    { token: "variable.source.md", foreground: colors.default },
+
+    // XML specific
+    { token: "tag", foreground: colors.lightRed },
+    { token: "metatag", foreground: colors.lightRed },
+    { token: "attribute.name", foreground: colors.peach },
+    { token: "attribute.value", foreground: colors.green },
+
+    // JSON specific
+    { token: "string.key", foreground: colors.lightRed },
+    { token: "keyword.json", foreground: colors.blue },
   ],
 
   colors: {
     "editor.background": "#282c34",
-    "editor.foreground": "#abb2bf",
+    "editor.foreground": colors.default,
     "editorLineNumber.foreground": "#636d83",
     "editorCursor.foreground": "#636d83",
     "editor.selectionBackground": "#3e4451",
diff --git a/assets/webpack.config.js b/assets/webpack.config.js
index 813e94ba6..5bb1f6a0a 100644
--- a/assets/webpack.config.js
+++ b/assets/webpack.config.js
@@ -51,7 +51,7 @@ module.exports = (env, options) => {
       }),
       new MiniCssExtractPlugin({ filename: "../css/app.css" }),
       new MonacoWebpackPlugin({
-        languages: ["markdown", "elixir"],
+        languages: ["markdown", "elixir", "xml", "json"],
       }),
     ],
     optimization: {