Fix/13608 wrong hover color in query select dropdown for certain themes

[``* `#13608` Wrong hover color in query selection dropdown for certain themes``](https://community.openproject.org/work_packages/13608)
I'm not sure the end of the file after general OpenProject colors is the best place in this file to add these colors, I think there's a better place above with things more related to a drop down menu to put these.