Change menu item hover color doesnt work

Hello, My problem is like described in the topic. I followed the instruction on themeisle’s guide on their website. My header background and menu item’s color changed and works fine. The menu items hover did not change and stayed at default (white) so when I mark an item it obviously becomes invisible… (white backgroud). I would like either to erase the hover completely or change its color to black.

Thanks for any help.