Right, the WD390U projector projecting just over a 5 foot diagonal image with four lights with the equivalent of 240 watts of incandescent lighting) illuminating our small, 10x11 foot testing room. Two of those lights are shining down onto the computers and projector. To get a handle on how bright, both the MacBook and the iPad have their displays set for maximum brightness. The room looks fairly dark, so that the projected image isn't badly overexposed. Elsewhere in this review is a picture of the hardware we used, the lighting was the same, only the exposure different.
"Back in the Day" - let's say the year 2000, big 30 and 50 pound projectors used for "rental and staging" - such as in use in hotel ballrooms and auditoriums, typically were only 2000 lumens! True, lights would be out to handle 25 foot screens, but consider today, we have a sub 10 pound projector that's brighter than those beasts of old.
Presentation mode is very usable for most applications, but if you do need better color, it really starts with Standard Mode, and gets really good in Theater, although you are giving up about 3/4 of brightness by the time you get to Theater mode.