yea, I think you're gonna have to resign yourself to the fact that there are no bright line distinctions between the two Since the whole species seems to be just one continuum of populational clines, its no surprise that the two look so similar
At the request of JP, I have been asked to share my experience as I have worked with both of these.
Obviously, the head color is different.
Orange have a goldish, yellow-orange coloration. OH are a bright reddish-orange.
Looking at the back ...
The pattern on the Orange tends to extend down the majority of the back.
OH, the pattern does not in MOST cases.
Additionally, the pattern on the OH is much finer compared to the Orange.
Lastly, (which is not represented well here), OH body color tends to be much darker than the standard Orange; almost black sometimes.
Orange body tends to be a tad lighter blue.
Mark has explained his opinion on differences as well.
There are also some small behavioral & reproductive differences too, but that's for another discussion.
Another sad revelation that has been discovered recently, is that it seems documention of these in the past has been lax ... which has unfortunately led to many people mixing these two together; and as we all know, should not happen which has further limited the gene pool ... and calls into question any offspring acquired in the hobby recently.