diff --git a/CLAUDE.md b/CLAUDE.md
index 020460cf..278d99c0 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -57,6 +57,10 @@ java -jar cameleer3-server-app/target/cameleer3-server-app-1.0-SNAPSHOT.jar
 - K8s probes: server uses `/api/v1/health`, PostgreSQL uses `pg_isready`, OpenSearch uses `/_cluster/health`
 - Docker build uses buildx registry cache + `--provenance=false` for Gitea compatibility
 
+## UI Styling
+
+- Always use `@cameleer/design-system` CSS variables for colors (`var(--amber)`, `var(--error)`, `var(--success)`, etc.) — never hardcode hex values. This applies to CSS modules, inline styles, and SVG `fill`/`stroke` attributes. SVG presentation attributes resolve `var()` correctly.
+
 ## Disabled Skills
 
 - Do NOT use any `gsd:*` skills in this project. This includes all `/gsd:` prefixed commands.