You should set configuration to not use VM dropdowns. ... if you want UIkit once. There is a setting for this in VM configurations - Templates and where you can choose jquery ... right down corner. There is one for dropdown. untick that
Its all settings in the Customizer. Its very hard to find things there though. But all of these hover settings and color settings are there.
You can also override them. If you use Firebug for Firefox or Chrome its pretty easy to find what css class is the one that you need to change to get the behavior you want. All templates from YOOtheme are not as well set with these kind of settings from start.
Excuse me, initially I did not quite well-formed question.
My concern is not the color, but the problem of framing buttons when you hover.
Please look at the new video may be able to help you with this problem.