Yes you can, and it's really easy to do. It's in full edit mode and you just select b&w with selective colouring.
I'm shockingly bad with PSE and even I can do that :)
i love elements 9:) it is easy to do the color select under the smart brush tool...you click on that and then you have a choice as to which color select you wish to do out of 5 variations...very user friendly:) HTH
I'm shockingly bad with PSE and even I can do that :)