Change background color on one page

https://finnskogutstillingen.squarespace.com/

password: finnskogutstillingen24

I am trying to change the background color on the "billetter/tickets" page via Page Settings/Advanced:

<style>
.main
{
  background-color: #000000 !important;
}
</style>

Also tried this:

<style>
#collection-6553c92c6b412969a9928874
{
  background-color: red;
}
</style>

Any ideas?
 

@Web_Solutions that worked, thanks! How did you find ".section-background"? I looked developer tool and Squarespace ID finder.

3 minutes ago, gullbekken said:

@Web_Solutions that worked, thanks! How did you find ".section-background"? I looked developer tool and Squarespace ID finder.