diff --git a/app/views/scodoc.py b/app/views/scodoc.py
index e5cdc7719..e65c4e666 100644
--- a/app/views/scodoc.py
+++ b/app/views/scodoc.py
@@ -374,7 +374,7 @@ def ue_colors_css(formation_id: int, semestre_idx: int):
         ":root{\n"
         + "\n".join(
             [
-                f"--color-UE{semestre_idx}.{ue_idx+1}: {ue.color};"
+                f"--color-UE{semestre_idx}-{ue_idx+1}: {ue.color};"
                 for ue_idx, ue in enumerate(ues)
                 if ue.color
             ]