man-pages input, how to forward esc seq to tty output dev

Hi All
I got a tool producing man-pages, i.e page that will be displayed by man(1)
on tty device UTF8 capable with SGR's (namely vt100 emulator)

In my generated man-page (that will feed groff...grotty) I'd like to be
able to emit ledgit escape sequence (again when in tty mode) but I can't
find a way to emit the exact color I need. (Or other attributes)

Is there any advise.

So far I tried
Here is text in \*[red]red\*[], \*[green]green\*[], and \*[blue]blue\[].

But I never get it either with
man -l foo.1
groff -man -Tutf8 -c foo.1

Thanx in advance.
Cheers