Hi Sally….for the page titles, you have a theme option setting available:
Go to Appearance >> Customize >> Colours >> Post & Page Titles
However, this will do all the titles for pages and posts, but if you want to change just the h1 headings only, then you need to do some custom CSS. If you are using jetpack, then use the “Edit CSS” under the Appearance menu and do some custom CSS for just “in-page h1 tags” like:
For the sidebar text, then this CSS needs to target that column container:
Of course, you would use whatever colour you want.