No. Not automatically, at least.
As stated in the UberMenu product description
UberMenu will not automatically adopt the style of your theme, unless your theme has an UberMenu-specific stylesheet. You’ll need to customize the styles on your own to recreate it if that’s what you want
Why?
UberMenu replaces your existing menu, to create a mega menu instead of a flyout menu. The theme’s menu styles include not only colors, fonts, etc, they also include positioning and sizes for submenus – you can’t merge the two without breaking the mega menu functionality. In fact, when the theme’s styles continue to affect the menu after UberMenu is activated, this is known as residual styling and needs to be eliminated.
I still want my menu to look like my theme and not like UberMenu
You have several options to customize UberMenu as you like.
Please understand that as these are customizations, we cannot offer support for this in the forum (what is supported?). If you need customization assistance, consider contacting a trusted freelancer.
Use an existing similar skin
UberMenu includes over 20 preset skins, and there are additional skins available for purchase in the UberMenu Skin Packs, such as the flat skin pack. You can test out all the available skins in the demos.
If you find an existing skin that is similar to your theme’s, you can simply tweak it with custom CSS
The Sample Custom Skin can be useful as well.
Use the Customizer
If you’d like a WYSIWIG experience where you can set colors, font sizes, etc, through the Control Panel, use the Customizer interface to create a similar style.
Write a Custom Skin
If you want full control over how your menu looks, you can Create a Custom Skin. You can either write it from scratch or base it on an existing skin.
If you are familiar with LESS, you can Custom Skins with LESS