The small icon to the right of the post content, that indicates the presence of a highlight &/or a comment, practically disappears against my background. Can I somewhere easily alter the css controlling that?
Whenever you want to change the style of any part of the theme, use Chrome or Firefox and right click on the area you want to change and choose Inspect. That will bring up a console that shows exactly which lines of CSS in exactly which files affect that element so that you can go in and change the style how you see fit. You can make the change directly to the style.css file via a text editor, or you can add the changes to the Custom CSS theme option so that the changes don't get overwritten if you update the theme.
Excellent Thank you.