Change header image on Xeiro theme

http://www.virtualizationstrategies.com/wp-content/themes/xeiro/images/banner.jpg

rename this image
take an image that size and name it banner.jpg and upload it to the above spot
/wp-content/themes/xeiro/images/

I am trying to change the background color to black, however, there is a section at the top of the theme that doesn’t change when I change the color code. I can’t find it in the code where to change this, does anyone know?