Contact Button graphic…where is it?

I have found all of the other pink graphics that I needed to change the color of…but the one button that eludes me is the button on the Contact Form page.

All of the other graphics were in the “/wp-content/themes/simplenbright/library/images” folder – but the contact button isn’t in that folder.

Does anybody know where it is located, or which CSS file controls the color of that button?

Thanks!