Missing Secondary Colors option

I have both a primary menu, and a secondary menu on my website. I can only see options to adjust colors for the primary menu, and not the secondary menu.

While in Customizing > Layout > Secondary Navigation - I click on Colors, and nothing happens, but if I click on Typography or Backgrounds, those links will take me to those options.

While in Customizing > Colors - it shows the following: Global Colors, Body, Header, Primary Navigation, Buttons, Content, Forms, Sidebar Widgets, Footer Widgets, Foot Bar. I tried clicking through the available options to see if maybe Secondary Navigation was hidden under one of them, but no luck. How do I get these color options for the Secondary Navigation to appear?