This css works. For example, for header level 2.
Likewise for other levels.

The a.twosharps is needed only if some of your h2 entries in the body is an anchor <a ...
(I needed that; probably nobody else does).
In that case in the h2 entry use <a class=twosharps ...

h2{   /* elements (tags)*/
  font-size: 20pt;
  color: darkgreen;
  font-style: italic;
}
ul[data-tag="2"] {
  color:darkgreen!important;
}
a.twosharps{
  color:darkgreen!important;

}