Editing Theme File, Crashed Website?

Hello all,

I was editing a blog of mine on WordPress at https://jonathangcameron.com/ and went into custom-header.php and wanted to edit the color on the header bar of the website. The theme is a free theme on WordPress called Flatter. It initially read:

//If no custom options for text are set, let's bail
//get_header_textcolor() options: HEADER_TEXTCOLOR is default, hide text (returns 'blank') or any hexvalue
if ( HEADER_TEXTCOLOR === $header_text_color ) {
        return;
}

I edited the portion ” === $header_text_color ” to say ” === #0f5971 ” and when I hit Update File to see the changes, the website showed this error message.
__

“Parse error: syntax error, unexpected ‘return’ (T_RETURN) in /home/camerondowning/public_html/jonathangcameron.com/wp-content/themes/flatter/inc/custom-header.php on line 43”
__

How can I fix it? I can’t even log into the WordPress site to undo any changes.

Regards