Unfortunately, I can’t see screenshots that you provided – http://prntscr.com/oahfry
Please describe the problem in more details with screenshots.
Try to use such screenshot maker as Lightshot https://prnt.sc/
Settings for this button comes from Theme Options > Styling > Customize buttons > Dark buttons options. Unfortunately, there is a bug with text color for the button, provide us with temporary wp-admin and FTP access, so we can fix it on your site.