HTML Code problem – I edited now pages blocked

Hi,
I wonder if anyone can help. I created 6 or 7 sites a couple of years ago with WordPress, but am now editing a relative’s site but a disaster has happened and I can’t see the site at all.
I wanted to change the text on part of the site from gray to black. I normally have no problem but I just couldn’t see how the pages were set up (I didn’t do it. Some text in the right hand side bar where the text in a widget would be, needed changing but I couldn’t find any widget in use so I looked in ‘Editor’ on the left hand side of Dashboard.
I then looked under
theme-widgets.php
Within the HTML coding, I saw the heading text that I wanted to change to black (but it wasn’t the right text):
I added the coding for ‘black’ thinking it would change to black, but I got the following error:

Parse error: syntax error, unexpected ‘<‘ in /home/comwater/public_html/wp-content/themes/vulcan/include/theme-widgets.php on line 70

The coding (with that of above and below) is:

));
register_sidebar(array(
‘ID’ => ‘bottom’,
‘name’=>’bottom’,
‘before_widget’ => ‘<div class=”footer-widget”>’,
‘after_widget’ => ‘</div>’,
‘before_title’ => ‘<h3>’,
‘after_title’ => ‘</h3>’
));
/* More About Us Widget */

class PageBox_Widget extends WP_Widget {
function PageBox_Widget() {
$widgets_opt = array(‘description’=>’Display pages as small box in sidebar’);
parent::WP_Widget(false,$name= “Vulcan – Page to Box”,$widgets_opt);
}

What I did was add the HTML for black to the line as follows:
/*<font color=#000000>More About Us Widget */</font>

When I realised my error, I deleted the HTML I had put in but then the pages went blank and I can’t see anything.

Does this mean that it can only be rectified by going into the hosting and using an FTP to do something? I can’t remember what I did when I was creating my sites, but it’s quite urgent as it’s a business site and my friend won’t be too pleased. I’m not hosting the site, so would the person hosting it need to do what is needed?

The theme is Vulcan. I can’t even get into any pages via the dashboard.

https://www.completelywater.com

I would appreciate any help. Thank you. Off to bed now but I’ll check in the morning.