diff --git a/atom/browser/api/atom_api_system_preferences_mac.mm b/atom/browser/api/atom_api_system_preferences_mac.mm
index 8ce71ff4f818b..ef2a0532e2ba5 100644
--- a/atom/browser/api/atom_api_system_preferences_mac.mm
+++ b/atom/browser/api/atom_api_system_preferences_mac.mm
@@ -106,10 +106,11 @@ AVMediaType ParseMediaType(const std::string& media_type) {
 }
 
 // Convert color to RGBA value like "#ABCDEF"
-std::string ToRGBHex(NSColor* color) {
-  return base::StringPrintf("#%02X%02X%02X", (int)(color.redComponent * 0xFF),
-                            (int)(color.greenComponent * 0xFF),
-                            (int)(color.blueComponent * 0xFF));
+std::string ToRGBA(NSColor* color) {
+  return base::StringPrintf(
+      "%02X%02X%02X%02X", (int)(color.redComponent * 0xFF),
+      (int)(color.greenComponent * 0xFF), (int)(color.blueComponent * 0xFF),
+      (int)(color.alphaComponent * 0xFF));
 }
 }  // namespace