diff --git a/conf.yml b/conf.yml
index 91f18ba..cec4fc3 100644
--- a/conf.yml
+++ b/conf.yml
@@ -22,7 +22,7 @@ sections:
 
       - type: iframe
         options:
-          url: https://calendar.google.com/calendar/embed?height=600&wkst=1&ctz=Asia%2FTokyo&showPrint=0&showCalendars=0&showTitle=0&showTz=0&src=bnl4YWZpcUBnbWFpbC5jb20&src=Y281dTVpOTVubmg4am10bXVlY2hpMW1nMTBqNmVia2pAaW1wb3J0LmNhbGVuZGFyLmdvb2dsZS5jb20&src=ZW4uamFwYW5lc2UjaG9saWRheUBncm91cC52LmNhbGVuZGFyLmdvb2dsZS5jb20&src=Y3NuYzhlYjVyczYxcmk0MG1zZGRnZHU5dTd2c3E2cGRAaW1wb3J0LmNhbGVuZGFyLmdvb2dsZS5jb20&src=bTFtZHA2Y3Q4N2poMDdxdnRiamFuM3NkOTloZXRlZnBAaW1wb3J0LmNhbGVuZGFyLmdvb2dsZS5jb20&color=%237986cb&color=%233f51b5&color=%230b8043&color=%233f51b5&color=%23f6bf26
+          url: https://calendar.google.com/calendar/embed?bgcolor=%23000000&height=600&wkst=1&ctz=Asia%2FTokyo&showPrint=0&showCalendars=0&showTitle=0&showTz=0&src=bnl4YWZpcUBnbWFpbC5jb20&src=Y281dTVpOTVubmg4am10bXVlY2hpMW1nMTBqNmVia2pAaW1wb3J0LmNhbGVuZGFyLmdvb2dsZS5jb20&src=ZW4uamFwYW5lc2UjaG9saWRheUBncm91cC52LmNhbGVuZGFyLmdvb2dsZS5jb20&src=Y3NuYzhlYjVyczYxcmk0MG1zZGRnZHU5dTd2c3E2cGRAaW1wb3J0LmNhbGVuZGFyLmdvb2dsZS5jb20&src=bTFtZHA2Y3Q4N2poMDdxdnRiamFuM3NkOTloZXRlZnBAaW1wb3J0LmNhbGVuZGFyLmdvb2dsZS5jb20&color=%237986cb&color=%233f51b5&color=%230b8043&color=%233f51b5&color=%23f6bf26
           frameHeight: 600
           frameWidth: 800