Menu color option disappeared

Hello,
It is always recommended to make child theme to make changes to your website.
You might have to reactivate Modality theme again using following Steps:
1.Click on Appearance ? Themes>> Activate other theme than Argent.
2.Again,Click on Appearance ? Themes>> Hover the Mouse over Active theme>> Click the “Theme Details” button.
3.Click Next Arrow button on the top left side of theme until you find Argent. Click Delete button
4.Go to Appearance ? Themes>> Add New >>Upload Argent theme. Activate the theme.
Now, check customizer section of theme again to see if your issue is resolved by doing so.

Nothing ?? Is there someplace in editor I can correct this?

Hi Amaclean23 – could you provide a link to your site running Argent so I can take a look? The only colour customization option in Argent I’m aware of is in the WordPress.com version. Is it possible you set up a WordPress.com site running Argent initially?

If you’re running Argent on a self-hosted site you can change the menu background colour with CSS.

.menu-primary-container {
  background-color: #bb00bb;
}

You can replace the example purple with any colour code you like.

Don’t edit the theme files directly, otherwise your changes will be overwritten every time the theme is updated to the latest version.

An easy way to add custom CSS is to install the Jetpack plugin and activate the Custom CSS module. You’ll then add your custom CSS in the new stylesheet editor that’ll appear in your dashboard, under Appearance > Edit CSS.

As alternatives, you could either install a standalone custom CSS plugin, or create a child theme.