I can't help with the personal esthetic preference, of course, but some reflections on color anyway.
There are four colors for the baseline series. Not all pieces exist in all colors. There is black, olive, mocha and Crystal. Crystal (a light blueish grey) is discontinued. In my eyes it is one of the most beautiful luggage colors out there, next to Andiamo's steel grey (a dark grey with a blue-green cast).
Black: Shows no scuff marks. Great for checked luggage. Will show dust. But dust is easily dusted off. Will hardly show stains. Everyone else's luggage is black. Need to customize a little with a luggage tag or duct tape to easily pick it out at the baggage claim. Has an upscale but understated look if not very original.
Olive: Shows very little dust. Will show scuff marks. Those are way harder to get out than dust. Not so ideal for checked luggage but easy to spot. Has a safari look.
Crystal: Very nice look. Upscale but not screaming look at me. Dust won't show. Stains and scuff marks will be very visible. More so than olive even. Best to use for hand luggage only or get a luggage cover if you don't like to live with scuff marks. Can be had on discount at londonluggage.
Mocha: possibly the most practical color out there. Elegant but different yet not loud. Will show dust less than black. Very good for stains and scuff marks. Easy to spot on luggage claim because there isn't much luggage around in that color. Possibly the best color for checked luggage.
Till