Use better secondary color for navigation

[benjaminoakes]

The green navigation bar started off by being gray. You can see the secondary, darker gray still in the hover state and the lines in the above screenshot. We need to use a green that works better in the palette. (Either darker or lighter; use your eye to decide on one.)

Tip: use responsive design mode in a desktop browser to test the dropdown nav.

Acceptance Criteria

• The dark gray will no longer appear in the top nav on any page. It will be replaced by a darker or lighter green that "looks good."
• Screenshot of fix in pull request

[mattigilmore]

http://www.colourlovers.com/palette/4466649/mountains.
http://www.colourlovers.com/palette/4466541/Test_Shred
if you don't like those two or browse the website you will find something you love