User blog comment:Sarah Manley/Test the Expanded Wiki Navigation/@comment-1091639-20111003202158/@comment-1613840-20111003231208

HI - A couple of answers
 * The transparent strip is an intentional visually divider
 * The contribute button uses styling for "secondary" buttons
 * Thanks for letting us know about the low screen resolution issue
 * The wiki nav color (the bar you see) shares colors with the primary buttons.