Catherine Zeta-Jones showed off her natural hair on Thursday and hinted at a possible transformation – sparking a huge fan reaction.MORE: Catherine Zeta-Jones' sprawling garden at $4.5million New York home looks like WonderlandThe actress posted a photo showing her with her natural curly hair, and wrote: "So, how's your hair today? #doblondeshavemorefun." WATCH: Catherine Zeta-Jones 'in a twist' in new bikini videoHer followers were quick to comment on the off-duty look, and of course, they were