Customizing Block

On the right there is a colors customizer, but it changes the color for the full site.  How do I customize just the menu bar with a background color, and likewise how do I customize the html block I added?  When I select a block the color options are greyed out?? How do I change fonts? How do I change font size? There doesn't seem to be a way to edit an element within a group separately. I don't see any patterns options at all.  They are missing.