Like this as in screenshot?

This is my website: Clockswally.comI want to do something like this website has done: decorum.pkThe header should invert color on hovering like in the decorum website.How to do that?Like it's white and then change into black when hovered upon it 

let me try 

No, I want to reduce the header as a whole. Not only logo

My website is soonnex.com I want to reduce header height, a little higher than the logo itself. No option in customization. Please help