My mind was set on the Sand when I got my first Domke (the F-6), but the store was just out of stock. I had to get my order through quickly (a large order together with others), so I got the Olive one instead. The plan was to sell it later and get one in Sand, but when I got the bag and saw the color in real life... I had to keep it, it was just too nice.
Every new Domke since then have been Olive, but I´m hoping that will change, as the next one will be in Wax Wear, preferably an F-3x.
I would also say that the Olive draws less attention than the Sand, if you don´t dress in light brown clothes all together.