Moved from the Creative Cloud to the Photoshop forum. They will be able to help you here.
Do you mean photoshop elements 11 or photoshop cs4 (photoshop 11)?
Anyway since you posted about photoshop elements 11 before.
Select the Expert Mode
Select the Brush Tool
In the Tool Options under Brush Settings use the Hue Jitter
(select different foreground and background colors at the bottom tool box)
thank you very ; ) thats it.