I don't want to give you the 'H' word since it only brings disappointment but if it makes you feel better, the grey slot actually looks like it has a blue-ish tint giving it a steel blue color while the third slot now looks like a tint of salmon pink when I rewatched the end of the Hilde trailer. Hwang's outfit in his Libra of Souls portrait also matches up to the color of the fourth slot.
Hmm, this could be a white dress/blue dress colour discernment kind of situation, but if I see any blue in that, its just a very minimal amount of saturation in the background. But even so, I can't say I think you're wrong. Now, that spot could be Lizardman/Aeon, but are they really going to add a third sword and shield athenian before they add even one of the classic dao movesets. I mean...surely they can't be blind to how that would stick in the craw of a not-tiny portion of veteran players? After a complete snub of that portion of the fan/consumer base in SCV and nothing in the base build of this game or the first season? I mean, surely as fans of the series themselves, they realize how weird it is that neither he nor Yun-seong are in yet? So grey/white/blue/whatever, that spot has to be Hwang. Surely?
One thing I can say for certain is that I am so tired of drawn out reveals. Just tell us the season line up near the beginning of PR for the product, once the content is certain. There will be plenty for us to think anticipate and speculate about even once we know that. In fact, it will lead to more detailed and more enjoyed conversations if we aren't speculating about the absolute basic question of who it could be until not long before the release. They could still make periodic announcements about stuff, which would dash or confirm fan speculation and hopes for what the character will ultimately look like, but it would be more engaging and frankly, less obnoxious to be in the dark about what to even expect/discuss in terms of moves, mechanics and balance, because we haven't a clue who to even anticipate.
At this point, I think we can safely say this is a knowing, intentional stragegy on the part of PS/Namco PR, but I think it's a bad one. I think they're just in love with those reveal trailers of theirs and just don't want to change course on what they've done up until now in keeping the identities secret until the moment you hear the announcer say "HWANG!" (just as an example

) as that same old earworm epic fight music begins to trumpet. But the more I live with the massive months-long dead zones in messaging/info, the more I just wish they would tell us who is coming at the start of the season, whether they have trailers for the characters done or not. Either that or make sure you aren't totally telegraphing other characters for most long-time fans. There are moments lately I swear we are being trolled.