Blank section and section colors

Hi! I'm having a hard time understanding: 1) How do I choose each section background color individually? I can only choose colors on color settings (primary, secondary and so fort..) but I can't pick which of those will be displayed for each section. 2) Is there a blank section that can be used repeatedly? I have content that could use similar sections, but I'm running out of options as I enable them. Best regards Douglas