Cool white lighting with parcans

Hi guys, so I am currently designing an opera and the director wants cool white color lights as pictured in the link below. What gels would work best to achieve this color on conventional PAR46 and 16s?

http://66.media.tumblr.com/08c89964b5bdac30bcf1379b4afbe247/tumblr_mmpnq9uah21s2pri8o1_500.jpg