Yeah, you're right!
When I got my copy of OP2, it was in the silver shiny box. Looked really nice (nicer than a lot of game boxes nowadays, I have to say)
But yes after a while they stopped using the shiny stuff and the boxes were darker.
That reminds me, some day I should scan in the text of the manual and put it somewhere, just to give people something to print out (if they want a hardcopy)
It doesn't really contain much useful info though. It does have a unit reference, and the tutorial text, as well as some docs on the menu system, and the "What has Gone Before" text.
I still have my original OP2 cd, pretty scratched up but it works pretty well.
(Including the case with the Cyberstorm 'ad' on the back)