[O] Setting Face of clocking info in Modeline

[Jeff Rush]

I'd like to colorize/change the size of the clocked-in task info
displayed in the modeline.

I've found the org-clock-heading-function but can't quite figure out how
to wire in a replacement nor whether I can affect the face displayed
with it or just the actual content of the field.

I also found in a Google search the interesting
'org-clock-frame-title-format' implying I might be able to display the
clocked-in task info in the frame header, but no actual example of it
being used.

Is there a correct way of doing this and am I on the right trail?

-Jeff