Oh yeah, so it was ISO 8000 for the milky way and something like ISO 500 for the foreground. Color depth is sort of several different factors, atmospherics (light pollution, air glow, and the colors of the galaxies and stars themselves). Definitely have to balance the ISO with the shutter speed/aperture. At 14mm you can expose for up to 25 seconds without stars starting to blur, I have found that something a bit shorter than that, like 20 or 15 seconds with a higher ISO seems to bring out the colors possible without the use of something like an elaborate stablization/star tracking system. Then I spend a lot of time in post enhancing the raw image file, usually color is already there those and its more about balancing exposure.