diff --git a/frontend/src/App.css b/frontend/src/App.css
index e1a6724..da9c9d2 100644
--- a/frontend/src/App.css
+++ b/frontend/src/App.css
@@ -98,6 +98,8 @@
   --color-badge-cat-workflow-text: #6ee7b7;
   --color-badge-cat-mastering-bg: #4a1035;
   --color-badge-cat-mastering-text: #f9a8d4;
+  --color-badge-cat-music-theory-bg: #3b2506;
+  --color-badge-cat-music-theory-text: #fdba74;
 
   /* Genre pills */
   --color-genre-pill-bg: #1a1a24;
@@ -1204,6 +1206,7 @@ body {
 .badge--cat-arrangement { background: var(--color-badge-cat-arrangement-bg); color: var(--color-badge-cat-arrangement-text); }
 .badge--cat-workflow { background: var(--color-badge-cat-workflow-bg); color: var(--color-badge-cat-workflow-text); }
 .badge--cat-mastering { background: var(--color-badge-cat-mastering-bg); color: var(--color-badge-cat-mastering-text); }
+.badge--cat-music-theory { background: var(--color-badge-cat-music-theory-bg); color: var(--color-badge-cat-music-theory-text); }
 
 .badge--type {
   font-size: 0.6875rem;