diff --git a/desktop_env/evaluators/metrics/slides.py b/desktop_env/evaluators/metrics/slides.py
index f398045..4fa0cb2 100644
--- a/desktop_env/evaluators/metrics/slides.py
+++ b/desktop_env/evaluators/metrics/slides.py
@@ -250,6 +250,14 @@ def evaluate_presentation_fill_to_rgb_distance(pptx_file, rules):
             r1, g1, b1 = fill.fore_color.rgb
             r2, g2, b2 = _rgb
             return sqrt((r1 - r2) ** 2 + (g1 - g2) ** 2 + (b1 - b2) ** 2) / sqrt(255 ** 2 + 255 ** 2 + 255 ** 2)
+        elif fill.type == 5:
+            master_fill = _slide.slide_layout.slide_master.background.fill
+            if master_fill.type == 1:
+                r1, g1, b1 = master_fill.fore_color.rgb
+            else:
+                return 1
+            r2, g2, b2 = _rgb
+            return sqrt((r1 - r2) ** 2 + (g1 - g2) ** 2 + (b1 - b2) ** 2) / sqrt(255 ** 2 + 255 ** 2 + 255 ** 2)
 
         return 1
 
@@ -363,3 +371,6 @@ def check_page_number_colors(pptx_file, rules):
         return 0
 
     return 1
+
+if __name__ == '__main__':
+    print(evaluate_presentation_fill_to_rgb_distance(r"C:\Users\tianbaox\Desktop\DesktopEnv\cache\3b27600c-3668-4abd-8f84-7bcdebbccbdb\lec17-gui-events.pptx", {"rgb": (0, 0, 255)}))
\ No newline at end of file