Kinda late to the party, but awesome find! The gray/white debate reminds me of the coat Han had on Hoth, where people swore it was blue, when it actually wasn't.
As far as the argument about what the "public expects to see", I don't think that holds much water.
It's almost 30 years later and they got about what? Maybe a minute total of screen time? I'm thinking the majority of the public won't even remember them at all, rather than whether they were gray or white. None of them seem to say anything when they see the Shadowtrooper, Shadow Scout, Shadow- [insert name here], and they weren't even seen in the films.
If it ended up the TK's were actually gray, maybe you'd have a point- but not a character that got so little screen time.