Preview - Highlight Text Color - Keyboard Shortcut

Hi!

I've loving the markup capabilities of Preview in Mountain Lion and was wondering if there was a way to quickly change colours (colors) of the highlighted text via keyboard shortcut?

I found this thread for Snow Leopard, but couldn't figure out how to get it to work for Mountain Lion:

https://discussions.apple.com/thread/3180984?start=0&tstart=0

It seems there are some shortcuts possible, for instance when I click the Markup dropdown box if I type "g" it will highlight Green, "b" it will select Blue etc. But it won't actually select these options.

The quickest way I've found is the right-click after highlighting which brings up a contextual menu to select the colour of that highlight.

Ideally I'd press a shortcut combination to change the highlight colour before selecting what to highlight. Does anyone know of a way to get this functionality?

Thanks so much for your help! =)

Derek.