set top navigation bar background color in woocommerce

how to set top navigation bar background as a infinite like this image
http://home.iitj.ac.in/~ug201210024/bar.html
in this image we can see when we minimize the website the background color is still like a infinite
or see this website http://www.flipkart.com/ (background of navigation is infinite width)

but in woocommerce background color of top navigation bar is a limited width
like in this image
http://home.iitj.ac.in/~ug201210024/bar2.html
so how to set top navigation bar color infinite

also i tried to increase top navigation bar but then get problem like
all window size is increase like this image
http://home.iitj.ac.in/~ug201210024/bar3.html

and i am using woocommerce and wootique

https://wordpress.org/plugins/woocommerce/