Susan

To change the background colour of the menu that appears when the user clicks on on hamburger Menu

Open (double click) on the menu object, then select hamburger menu

Select background, then select the background colour.

You may need to select menu item, item on mouseover, etc and in each you can select the background colour (or transparent) and text colour.

This will need to be done for each individual menu object (eg sidemenu and stickybar) and for each resolution.

I am not sure what you mean by thye menu box showing up twice, is it possible to provide a screen shot??

BTW, did you realise that if the sidebar is wide enough (template, template structure), and you drag the menu object wide and deep enough (template, template content, siderbar), then your menu will appear as words at desktop resolution, for each lower resolution you can decide if you want the sidebar. You can add a menu object to the header at a specific resolution, and it will only appear at that resolution and below if you wish.

Select menu item and it's colour, item on mouseover and it's colour, etc

You have probably discovered you need to set these colours independently for each resolution.

Oops - I misled you!!

The colours you select for the hamburger menu (drop down) will be the same for every resolution.

My apologies - on the project I was using I had multiple menu objects (a different one for each resolution) that were part of a test I was carrying out. This is a handy feature, but it lead to me giving the wrong answer I'm sorry.