Getting closer towards some working code. I've expanded the list of automatically created pango style text tags to include those which are possible using the GtkTextView widget. One nice feature in pango, ie using unique strikethrough colours isn't available as a text tag attribute. The fg/bg colours are restricted at the moment to red, green, blue, cyan, magenta, yellow, black, gray and white. Apart from the default theme font, the other two settings are serif and sans. Setting unique values for these would not be an impossibility, but these can be created on the fly as normal text tags in a Tcl script.