diff --git a/web/chat/text-message.react.js b/web/chat/text-message.react.js
--- a/web/chat/text-message.react.js
+++ b/web/chat/text-message.react.js
@@ -73,7 +73,9 @@
       canReply={canReply}
     >
       <div className={messageClassName} style={messageStyle}>
-        <Markdown rules={rules}>{text}</Markdown>
+        <Markdown threadInfo={props.threadInfo} rules={rules}>
+          {text}
+        </Markdown>
       </div>
     </ComposedMessage>
   );
diff --git a/web/markdown/markdown.css b/web/markdown/markdown.css
--- a/web/markdown/markdown.css
+++ b/web/markdown/markdown.css
@@ -17,15 +17,16 @@
   box-sizing: border-box;
   width: 100%;
   margin: 6px 0;
+  border-radius: 8px;
 }
-div.darkBackground blockquote {
+/* div.darkBackground blockquote {
   background: #a9a9a9;
   border-left: 5px solid #808080;
 }
 div.lightBackground blockquote {
   background: #d3d3d3;
   border-left: 5px solid #c0c0c0;
-}
+} */
 
 div.markdown code {
   padding: 0 4px;
diff --git a/web/markdown/markdown.react.js b/web/markdown/markdown.react.js
--- a/web/markdown/markdown.react.js
+++ b/web/markdown/markdown.react.js
@@ -3,6 +3,9 @@
 import classNames from 'classnames';
 import * as React from 'react';
 import * as SimpleMarkdown from 'simple-markdown';
+import tinycolor from 'tinycolor2';
+
+import { type ThreadInfo } from 'lib/types/thread-types';
 
 import css from './markdown.css';
 import type { MarkdownRules } from './rules.react';
@@ -10,9 +13,10 @@
 type Props = {
   +children: string,
   +rules: MarkdownRules,
+  +threadInfo?: ThreadInfo,
 };
 function Markdown(props: Props): React.Node {
-  const { children, rules } = props;
+  const { children, rules, threadInfo } = props;
   const { simpleMarkdownRules, useDarkStyle } = rules;
 
   const markdownClassName = React.useMemo(
@@ -40,7 +44,19 @@
   );
   const renderedOutput = React.useMemo(() => output(ast), [ast, output]);
 
-  return <div className={markdownClassName}>{renderedOutput}</div>;
+  let darkerThreadColor;
+  if (threadInfo) {
+    darkerThreadColor = tinycolor(threadInfo.color).darken(20).toString();
+  }
+
+  return (
+    <div
+      style={{ background: darkerThreadColor }}
+      className={markdownClassName}
+    >
+      {renderedOutput}
+    </div>
+  );
 }
 
 export default Markdown;