Inline transformation of data would seem like the natural fit for SGML derivatives - it seems a shame that we've so often found the need to go with explicit graphs, decorations and indeed the just-gone situation of seemingly redundant HTML to help fight the CSS box model. :/

(cue responding comment(s) about XSLT, WPF, etc.)

Also nice call on the simple-as-possible colouring, there. :)