Once you select the 4 widget layout for the footer, you can set the widgets for each area under Appearance > Customize >Widgets > Footer Widget Area 1/2/3/4.
You can choose WordPress default widgets or can add third party plugin to add widgets in the list.
COLORS & BACKGROUND FOR FOOTER WIDGET AREA
You can set colors for Widget Title, Text and link in the footer under Appearance > Customize > Colors & Background > Footer Widgets
Note: Above colors will be applied to default WordPress widgets only. If you are using third party plugin to add widgets, you would need to manage colors from the plugin itself.
TYPOGRAPHY FOR FOOTER WIDGET AREA
Typography options set under Appearance > Customize > Typography > Base Typography will be applied to the footer widget area by default.
More options will be available with Footer Widgets Module with Pro.