Okay lets be fair. Yes, Quake could be said to be the progenitor of the bland gray/brown shooters, but the difference is that Quake isn't "bland". I feel that it was less a harbinger of FPS's to come, and more that it's a case study in the fact that a brighter color scheme wouldn't have fixed many of the shooters from the past decade or so. Obviously you can get away with a bland color scheme, otherwise Quake wouldn't be so fondly remembered by nearly everyone who played it. Heck, it took being reminded that Quake was actually kind of an ugly game (in your Clive Barker's Jericho review, I believe) before I realized that "Holy shit! He's right. Quake DOES have a very bland color scheme." Yet it's still a beloved classic despite that.
I think the problem is less the color scheme, and more that Quake wasn't using said color scheme in some vain attempt to pass-off as looking realistic. Quake knew its graphics were shit, but it also knew what kind of setting it was going for. Let's be honest, as much as you can make fun of Quake for having a lot of dull color tones, it would have felt like a completely different game if it used brighter colors.