That is not a Corvid issue for which this forum is for.
You are better suited going through Wix Support and reading the support pages for the Quick Action Bar.
https://support.wix.com/en/about-wix/contacting-wix-support
https://support.wix.com/en/article/adding-and-setting-up-the-quick-action-bar-on-your-mobile-site
Actually it’s possible to change it via Corvid using the style property:
https://www.wix.com/corvid/reference/$w.QuickActionBar.html#style
But unless you want to change it in specific situation, It’ll be easier to do via the editor.