Line under page title color issue

Hi – with the recent theme update, a setting on my website has changed and I can’t figure out how to fix it. This is the second time this has happened, but the first was so long ago that I can’t recall what was necessary to restore the color setting.

The line under each page title changed color. As you can see on this page link provided as an example of what is happening on all pages, the graphic line under the page title ‘Contact’ is now teal but it used to be the same color as the menu bar background – a shade of purple. Seems the default is teal and with the latest upgrade, it reverted. I can’t find where to change this setting or if it is a custom CSS, why did that disappear – and what would that css be? PLEASE HELP!

The page I need help with: [log in to see the link]