Problem with Menu and Footer

Hello! I wanted to ask you guys for a help.
I’m right now creating a website using Sydney for my friends’ band.
The problem i was talking about going like that:

How to create Front Site menu background transparent (without black color), becoming black after scroll, while having it black on all other pages?
I found a code like this on a forum:

    header#masthead {
        background-color: rgba(0,0,0,0.87);
    }

It works nice on pages, but make it black on FrontPage also- how to avoid that?

And the other quesiton, on few of my yet empty pages or with little content in it, it makes a big white background UNDER footer, any ideas how to delete it? E.g on pages like : Tour, Photos.

And the last thing, how to make whole page have same background? You can notice e,g on Video/Tour page that there’s white background under the grey one. Thanks you guys for help, it means A LOT for me!!!

Site: www.psycho-visions.com

Hello there,

Please try this CSS code:

    .home .site-header:not(.float-header) {
      background-color: transparent !important;
    } 

Regards,
Kharis