Customize block editor styles

Hi,

I’m not well-versed with going “under the hood” with WordPress but I’ve got v6.0.1 installed and, in my block editor, when I use a paragraph block and place a hyperlink onto a piece of text, due to the color styles of my theme, the link is the same color as my background and so is practically invisible.

I am looking for a means to edit the baseline styles of the paragraph block (or the link color in general) in the Gutenberg editor.

I saw the documentation about a theme.json file but I’m not sure how to invoke this rule in that file or if that’s the file I want to be editing. Perhaps there’s another section of the site where I can add a CSS rule but not sure what that rule would look like.

Anybody want to teach a man to fish? Point me in the right direction and help me to figure out how to customize styles in the block editor?

Thanks a lot,