diff --git a/AnoPrimer/evaluate.py b/AnoPrimer/evaluate.py
index 2453123..a2a0a02 100644
--- a/AnoPrimer/evaluate.py
+++ b/AnoPrimer/evaluate.py
@@ -395,7 +395,7 @@ def _plot_primers(self, ax, oligos):
                     )
                     ax.add_line(line)
 
-            patch = patches.Patch(color=pal[pair], label=f"pair {pair}")
+            patch = patches.Patch(color=pal[pair_idx], label=f"pair {pair}")
             handles.append(patch)
 
         return handles