Go to the Customizer -> Footer Settings.
There are several options that can help you determine the right colors match. Click on Footer Colors Options and a panel will expand, with the customization options:
Here are the different options explained:
Paragraph Color
This is the color specific to the text of the paragraphs.
Icon Color
This is the color of the icons in the footer (e.g. social media icons).
Icon Color on Hover
This is the color of the icons in the footer (e.g. social media icons), when hovering over them with the mouse.
Accent Background Color
This is the color of the last content box, which you can make more prominent by accentuating its color.