Header Menu change box color

I do have jetpack installed.
In the header where words home, about, contact appear top right hand side.
How do I change the color of the square box around the word.I can change the color of the word.
The square box now appears green.

I did find the answer to my question above. Thought I would share to help others save time.
To change to color around square box on header menu go to . . .
Appearance-Theme Options-Main- Change Element Color.
This also changes the image next to search bar.