diff --git a/src/main.tsx b/src/main.tsx
index 0ebfc1ae..c154d6b6 100644
--- a/src/main.tsx
+++ b/src/main.tsx
@@ -14,6 +14,8 @@ import localizedFormat from 'dayjs/plugin/localizedFormat';
 import {GlobalModel, GlobalCommandRunner, Session, Cmd, Window, Screen, ScreenWindow, riToRPtr, widthToCols, termWidthFromCols, termHeightFromRows, termRowsFromHeight} from "./model";
 import {isModKeyPress} from "./util";
 
+let IS_DEV = __PROMPT_DEV__;
+
 dayjs.extend(localizedFormat)
 
 const RemotePtyRows = 8;
@@ -2531,8 +2533,8 @@ class MainSideBar extends React.Component<{}, {}> {
         }
         let isCollapsed = this.collapsed.get();
         return (
-            <div className={cn("main-sidebar", {"collapsed": isCollapsed})}>
-                <h1 className={cn("title", "prompt-logo-small", {"collapsed": isCollapsed})}>
+            <div className={cn("main-sidebar", {"collapsed": isCollapsed}, {"is-dev": IS_DEV})}>
+                <h1 className={cn("title", "prompt-logo-small", {"collapsed": isCollapsed}, {"is-dev": IS_DEV})}>
                     {(isCollapsed ? "[p]" : "[prompt]")}
                 </h1>
                 <div className="collapse-container">
diff --git a/src/sh2.less b/src/sh2.less
index 364bc22a..49e88540 100644
--- a/src/sh2.less
+++ b/src/sh2.less
@@ -184,6 +184,10 @@ html, body, #main {
     white-space: nowrap;
     overflow: hidden;
 
+    &.is-dev {
+        background-color: darken(rgb(177, 0, 10), 30%);
+    }
+
     &.collapsed {
         padding-left: 1px;
     }
@@ -208,6 +212,10 @@ html, body, #main {
     background-color: darken(rgb(0, 177, 10), 30%);
     flex-shrink: 0;
 
+    &.is-dev {
+        background-color: darken(rgb(177, 0, 10), 30%);
+    }
+
     .menu {
         padding-top: 10px;
         display: flex;