Hi Chris,
You can change the navigation background colors to the Page setting -> Design -> Customize -> Select Red preset or if you already have one customize then it will show you the Customize Skin options. From there proceed to the 'Navigation' part where you can edit/select the color you want to edit.
As for changing the color for the Mobile Menu icon upon hovering the icon/button, we will try to release a newer version of the Crimson Theme next week to allow this customization.
Let me know if this helps.