feeds links on side bar not display properly

Hi there,
by design links in widget color is #777 (and #444 on hover), yes.
Though, some WordPress core widget are designed in a different way. E.g. links in the wp rss widget will look like links in the main content.

Anyway, you can always override this behavior with your own custom CSS that you can add in Appearance -> Customize -> Advanced Options -> Additional CSS

You might want to use a page inspector tool to get the CSS selector you need:
https://docs.presscustomizr.com/article/272-inspect-your-webpages-in-your-browser-with-the-development-tools