The Events Calendard body background color

I’m trying to get the body background of my events calendar details page to be white, just like all my other pages.
For some reason my blue header seeps down on the page, and I can’t seem to find a way that changes that part.

I’d like not to have a child theme for this supposedly small change. A quick CSS would be awsome.

See example here: https://ibb.co/dkqcqzw
The pink would be the preferred area to give a white color. Alternatively the yellow area is fine as well.
Note that I’m not trying to control the width of the white area, as that should just follow the css element’s width.

Does anyone have a good idea, for a usable solution that won’t go away with theme updates???

NB. Yes I have tried changing the epta-row epta-template-1 css, as that hits the area I’m trying to color. But it only works when I add it via chrome’s developer menu. But when I add it to files and quick css – it does nada.