Hi,
Here are the rules which define above background color:
.t3-header {
background-image: -webkit-linear-gradient(top, #5c58dc 0%, #4743d8 100%);
background-image: -o-linear-gradient(top, #5c58dc 0%, #4743d8 100%);
background-image: linear-gradient(to bottom, #5c58dc 0%, #4743d8 100%);
filter: progid:DXImageTransform.Microsoft.gradient(startColorstr='#ff5c58dc', endColorstr='#ff4743d8', GradientType=0);
background-repeat: repeat-x;
padding-top: 24px;
padding-bottom: 24px;
position: relative;
top: 40px;
width: 100%;
z-index: 4;
transition: padding-top 400ms, padding-bottom 400ms, box-shadow 400ms;
-webkit-transition: padding-top 400ms, padding-bottom 400ms, box-shadow 400ms;
}
and:
.t3-off-canvas .t3-off-canvas-header {
background: #4743d8;
color: #ffffff;
padding: 0 0 0 18px;
height: 56px;
}
You can override these and change to your desired color.