@zeeshan.rb
I use a panel with a gradient background color as a replacement for the default styled toolbar and navbar as described by @phapps. We will be introducing color, styles and themes soon. But in the meantime, a customized panel is the alternative.
Note that depending upon your UI layout the controls on the panel-replacement for navbar and toolbar may require adjustment of their auto-resize properties for them proper layout when the orientation of the UI changes.