I like both Presbys Crown Jewel and Loop the Loop but I'm wanting an iris that is white with Blue. Due to variations in the lighting of the photos I'm having a difficult time determining which would be more blue than purple. Is anyone familiar with both of these irises?

Crown Jewel looks to me to be more on the purple side.

Even blue iris are going to look purple in some light. Loop the Loop is definitely more a violet purple, while Presbys is a deeper bluish purple.

I don't think there are many plicatas that are a true blue. Someone know of any similar to these two but more blue?

Ink Patterns is much closer to blue than violet. It's also a great all around iris.

Sherri I grow both of the two that you mentioned. To me both of them are more on the purple side. Another that is more blue is Palace Beauty.

That really is a beauty!