Those should not be in your HTML. Those should only be done with CSS classes for modern HTML.
e.g.,
<table class="table tableborderX">
<tr class="trblue">
<td class="tdred">Content</td>
Likely the only solution is to use a search/replace adventure for updating each of those in your mysql dbase, either through phpmyadmin or a dbase editor plugin (making sure you have a full backup of the dbase first!).
I’m dealing with this myself with the pesky align tag for centered paragraph note at bottom of about 5% of our posts, usually related to a featured article editorial notice. Sigh.
I am going to try this plugin just to see if it works for this, although I know how to do it via phpmyadmin, it might be more convenient :
https://wordpress.org/plugins/better-search-replace/
(MAKE BACKUP OF YOUR MYSQL DBASE BEFORE TOUCHING IT!)
Thank you very much neotrope.
