Okay, how about I post a few images and tell me 
what your expert opinion is?

(Sorry if this seems like a lame excuse to 
display Ifurita cels, but I really am trying to 
learn something here. ~_~)

#3 - This is an example of something that would 
be a grey area for me.  I actually have a cel 
very similar to this scene (too bad my scanner's 
broken) that I positively know that it came from 
OVA II (but just because it included Makoto with 
his El Hazard 2 outfit & headband)... but 
Ifurita's hair is still in her original blue (not 
purple) color.  So what do you think about this 
particular cel?

(This image came from Yann's own Animanga site 
and is for educational purposes only.)