I'd be wary of anything TSSZ posts, honestly. Tristan, the owner of the website, has drummed up a
very negative reputation around most Sonic fansites.
I mean, hell, every time he writes anything about the fangame I'm helping out with,
Sonic Robo Blast 2, he makes absolutely sure to play up the
drama of the original programmer, SSNTails, stepping down, despite the whole thing being fairly undramatic at all (he has a kid now, so of course he has other obligations - hell, he still pops in from time to time). Then there's the time where a bunch of fangame designers all started having a conversation in an IRC chatroom about making one giant fangame together, while Tristan was present - it was all a giant joke, but Tristan took the story and
actually ran it. That's the problem in a nutshell - he's so desperate to be first with a scoop that he'll run anything, no matter how grounded in fact it really is.
Plus, he's citing a website that's banned on NeoGAF, which is in itself not a good sign.
That being said, I'm not sure where you'd obtain accurate sales for both
Colors and
Generations. I do recall hearing that
Generations was the most pre-ordered
Sonic game
ever, prior to its release (
there was even a NeoGAF topic to this effect), so I'd assume that
Generations will end up selling more in the long run.