Is your white ink running over your colors, more than usual?
If so, remember that humidity greatly affects the way the nozzles of the print heads fire. Lower humidity could cause your white ink to run loosely over your darker colors. To combat your white looking "soupy" over your darker colors, try lowering your White ink limit. If that doesn't help, try lowering your resolution or the Pass count, if you're printing with a commercial printer. - Stay Elegant