Hi I'm using the Dark Chocolate theme, and would like to change the default background color on text blocks. right now I am doing this by selecting the block going to design and then selecting the color I want. Rather then do this on every new page is it possible to edit the css or something to change the color.

on apoprecords.com you can see that the side panel and main section have a black background, but if I try to add a new page the background is is grey by default.