How to change the Error WordPress page when the site is down?

In wp-db.php is this part (the error message):
$this->bail("
<h1>Error establishing a database connection</h1>
<p>This either means that the username and password information in your <code>wp-config.php</code> file is incorrect or we can't contact the database server at <code>$dbhost</code>. This could mean your host's database server is down.</p>
<ul>
<li>Are you sure you have the correct username and password?</li>
<li>Are you sure that you have typed the correct hostname?</li>
<li>Are you sure that the database server is running?</li>
</ul>
<p>If you're unsure what these terms mean you should probably contact your host. If you still need help you can always visit the <a href='http://wordpress.org/support/'>WordPress Support Forums</a>.</p>
");

Please print what you have out there instead.
Not the whole file, JUST that part.

I realize that this is an old thread and the problem may have been resolved. However, this is the first (in the many that I have searched about customizing wp-db.php) that deals with specifics of HOW to go about doing so.

I don’t know for certain that this is the answer to fixing the parse error is to change the quotation mark into a single quotemark after bail( and before the final );. You will also have to escape the apostrophe in I’m sorry by putting a backslash before the apostrophe.

$this->bail('
<div align="center">
[...]
I\'m sorry but the <b>site is temporally down due to technical
[...]
');

I’m with davgam on this issue: http://wordpress.org/support/topic/36534#post-257124

It isn’t always a viable option to switch hosts. And it would be very nice if the error page could be easily made to match the look of the site that the wordpress blog is on rather than matching the look of wordpress.