diff --git a/cours/cours_beamer.cls b/cours/cours_beamer.cls
index 875a2a5..16c5137 100644
--- a/cours/cours_beamer.cls
+++ b/cours/cours_beamer.cls
@@ -80,7 +80,7 @@
 \colorlet{definition}{red}
 \colorlet{theorem}{red}
 \colorlet{property}{red}
-\colorlet{proof}{purple}
+\colorlet{proof}{violet}
 \colorlet{vocabulary}{blue}
 \colorlet{remark}{red}
 \colorlet{method}{orange}