Matching colors to prototype photos is tricky business, to say the least. Colors can look very, very different depending on what time of day the photo was taken and whether the sun was in front of or behind the subject. Brown can look very red-orange if it is front-lit in late afternoon sun, but the red will disappear in a photo taken at 11:00 a.m. with the car side in shadow. A freshly painted car looks very different from one that's been out in the sun for a year or two, even if it's clean.
This is a problem both for the manufacturer trying to get a good paint match and for the buyer who wants a prototypical-looking model. Browns, oranges, and yellows are probably the most difficult to get right when working from photos, because they are the most affected by the daily variation in the color of sunlight. I suspect that a lot of the people who select and compound these paint colors do not have the experience and "vision" to get a good color match out of a pile of photos.