So, it turns out, the simplest way would be to add this to the headers of the discourse instance that show up on the embedded code:
<script>
window.document.domain = "the.domain.name.of.the.blog.com";
</script>
This would then allow javascript on the blog page to alter the css for the iFrame, b/c it gets around cross-domain restrictions.
But, I customized the Header, Footer and every section of the Admin > Customize > CSS/HTML with that bit of code, and it does show up when i look at the site itself, but when i view the source of the embedded comments, that bit of javascript is gone, hence i can’t change look and feel.
It seems to me that the customized attributes should also flow forward to whatever code gets embedded elsewhere.
Thoughts?
Thanks as always.
m