In order to change header you need to change mini menu bg color and navigation background color.
Please follow these instruction to change color header to the color you want:
Change mini menu color
1. Go to this file: /app/webroot/css/custom.css
2. Add these line
.header-bg{
background: #257BBA; -> change the color code you want like: #33333
}
.sl-navbar{
background: #257BBA; -> change the color code you want like: #33333
}
