listen to Venutus1 he knows his stuff
Yea. 6.5 would (should) be a "crisp" white daylight.
If it looked blue, that would be funky.
I don't know how big your vivs are overall... but if I were using that light, I would see if I couldn't get the bulbs to come on in sequence and then go off at night in sequence.
That way the frogs could get a more natural light intensity curve throughout the day.
It may not be possible though with that fixture...because it looked like all went through one power cord.
Unless you are up for a little modding.