Customize Colors Not Changing in Version 1.4.4

I a trying to change the background color for my submenu and when I pick the color I want, it does not change. I tried picking several different colors and none of them are changing the background color. Here is my website:

https://EndlessSkyL3C.org

I’m trying to change the background color to a light blue so that is is easier to see instead of the white background.

Thanks.