White areas on home page

Hello, Could you please help me with a couple of things on my site? I've had a search around the forums but haven't found the specific answers I'm looking for. Can I make the header menu solid black, instead of transparent? If this is possible, will the 'featured image' (on the post pages) then display directly beneath the header, or will they be slightly hidden behind it? Can I change the color of the menu text? On my home page there is a white space under the header. How do I get rid of this? Thanks for any help you can give me! The site is: eggbananatravels.com