There is a site somewhere that has a list of colours and mixes for various machines.  Can't remember if it was Pinball Pal?????  Whitewater blue was included in the list though.

I will have a look, it had some good stuff on it but as mentioned earlier, it all depends whether your playfield is faded or not.

EDIT:  http://pinballpal.com/colors/  

Recommend this guy's stealth mylar as well....great product.  I have used it on all of my machines pretty much and it does a great job and peels off very easily.