Brand Bar background color visible with custom Nav color

[troyschneringer]

This is apparent especially when you choose the Nav color to be white as there is a thin black line across the bottom.

[nathanyoung]

Fix for this is implemented in the T3 project. The default color is overwritten via the custom color scheme css that's passed down via platform.

https://github.com/Tier3/T3/commit/342b91d43fe67fc05b60dadf7fc0e8fd21851248

fyi: @osbornm