Hello,
I have changed the header formatting and table title formatting in both concept and task template files of the XML file something like this.

I have italicized the table title and gave blue background to the table header. The same is getting reflected both in the normal DITA files and the PDF outputs.
But when I publish this in HTML5 output, the formatting is not getting reproduced.

The table with plain formatting is seen without blue background for the table header. I am not sure what's wrong in this. Can somebody help me how to proceed in this case?