Actually I heard a different story. It was supposed to be Donald Cameron directing Hikari (the person who directed COLORS), but due to schedule conflict he couldn't do it in the end, so hikki had to ask Kaz to direct the pv instead... I think this is what they said when she released COLORS (that Mr. Cameron finally directed her pv).
Edit: Yeah I checked JPN wiki, and my memory is right. Donald Cameron couldn't film Hikari.. I wonder what he would do to the pv if he did direct it
?
Source:
http://ja.wikipedia.org/wiki/%E5%85%...2%AB%E3%83%AB) (the fourth point)