I don't have info on this particular model, but there are a variety of ways that you can make a projector brighter without increasing the bulb wattage, all of them affects color performance, contrast performance, or both. Worth mentioning is: A more transmissive color wheel (which in turn decreases color saturation), a white segment in the color wheel (again, decreases color saturation), slower color wheel speed (decreases the off time of the DLP), a more open iris and light path system (decreases contrast, however I would think that W6000 already is pretty open in this regard), skewing the color balance towards green/cyan because that's where the bulb is most efficient (this has no effect on post-cal light output, since it's basically just a different setting). My guess would be a different color wheel at 4x speed, perhaps with a white segment. That's a cheap and easy way to get a lot more light, sacrificing color accuracy along the way. The big question here is how far did they go - it might still be a reasonable color performance compared to other high-output projectors in that price range. While purists probably won't be satisfied, I'd say that you could sacrifice some of the color saturation and accuracy without throwing the average user off.
One (imho) important note: There is a big difference between measuring a calibrated projector, i.e. measuring at D65 color temp, and having accurate colors at that setting. A lot of projectors can deliver fairly high light output even at D65 with completely screwed up colors, and then when you adjust primary/secondary saturation and brightness (if possible), or even gamma, the brightness decreases massively. High light output at accurate color is NOT an easy task, and just because you measure white at D65 and high light output, doesn't mean that you will be able to get accurate color and decent light output on a big screen. I've seen a lot of cheapo LCD projectors where people have been pointing towards reviews measuring fairly high "calibrated" lumens, however if you use the settings suggested in the review, the PQ is horrible. Set the projector to actually deliver an accurate color balance, and the light output is halved.