If you want to colour table cells, there is a workaround discussed here in the forum, some time ago.
There was a GitHub PR table parser add data attributes for easier styling #8175, which got rejected, because Jeremy thought it produces too much HTML code.
Since it would need to overwrite a core parser, I did not publish it as a plugin, because Maintenance problems.
You can comment at GitHub, but I am not sure if it would help.
Table formatting is probably the most complex parser we have in TW. So you do not really want to mess with that one
-m