...I dunno...there were a few blue scenes in the 
TV series as well, if I recall. It's hard to tell 
without a bigger scan...the biggest tip-off is 
the line-work. OAV cels shows the signature line 
value Noburteru Yuki loves, and that is also 
typical of older anime...not only color, but 
texture of lines defines certain things. The TV 
series lacks that linework, and is generally very 
clean and crisp. The color lines are also very 
sharp. All I can say is this: ask for a bigger 
scan. It's impossible to tell right now ^^;;

-Mish