I'd have though bleach would have have affected both inks my self.
I'm no ink expert I seem to think there's the bronzing test, not too
sure if it can only be done with the black ink... from what I understand
one bronzes the other doesn't.... I could be entirely wrong...!
There was a debate going one many, many moons ago on the old Forum... if
you fancy a scout through the 'printer articles here'
(
http://www.howtofixcomputers.com/bb/forum39.html) maybe you'll come
across it.
Please note this is an old forum and does not accept any posting.
davy