Customize Header for "Shuttershot" theme

Hello,

I need help to edit my css file. I am working on my theme.css. I am newby and I am just starting with css, so please be very specific and detailed in your explanation, I won’t guess what could certainly be obvious to others.

My page is currently running with the theme “shuttershot”:
http://www.rbliahassociates.com/mainpage

Below is an example of shuttershot:
http://jinsonathemes.com/fabs/?themedemo=Shutter-shot

1) I would like a white transparent strip for my menu:
(ex: http://klein-dytham.com/ )
Actually I want to turn the transparent black strip on the top the page (see link about “shuttershot” theme) to a clear white transparent strip.
I could only turn it to transparent (no color), but I don’t find any html code for transparent white (like the text on the pictures on my page)
This is my page: http://www.rbliahassociates.com/mainpage/

2) I would like my menu strip not to cross the whole page
(ex: http://klein-dytham.com/ )

3) I would like to change the color of the police on my menu (the word “archtecture”) to black.

Thank you for your help.