The higher the lightboost % the brighter the screen, so just set it at 100%. You do eliminate more motion blur with 10% LB but it's dim as fuck.
PixPerAn Tests on BENQ XL2411T and ASUS VG278H
baseline - 60 Hz mode (16.7ms continuously-shining frame)
50% less motion blur (2x clearer) - 120 Hz mode (8.33ms continuously-shining frame)
60% less motion blur (2.4x clearer) - 144 Hz mode (6.94ms continuously-shining frame)
85% less motion blur (7x clearer) - 120 Hz LightBoost, set to 100% (2.4ms frame strobe flashes)
92% less motion blur (12x clearer) - 120 Hz LightBoost, set to 10% (1.4ms frame strobe flashes)
source: http://hardforum.com/showthread.php?t=1734114
You get less motion blur with 10% lightboost but it may not be as noticeable as you think. It's your call whether a dimmer screen is worth it or not, but the only real fix is dim your room to make it seem like the monitor is brighter. The colours can be fixed by either manually calibrating it through nvidia control panel or using an icc profile. I would start by installing an icc profile and if you still see inaccurate colours then you should manually correct it.
You can find some icc profiles for the asus here: http://hardforum.com/showthread.php?t=1730425