So, from this narrow survey, it seems that color may be the least important factor when one decides to buy a Shelby. That's how it is/was for me. When I was in the market, my critical factors, in descending order, were:
1. body style (convertible)
2. transmission (4-speed)
3. year (1st 1966, 2nd 1968, 3rd 1969/1970. The '66 convertibles were too rare to be a practical)
4. engine (1st big block, 2nd small block)
5. available options (air conditioning, tilt/swing away steering column, upgraded factory or after market radio, factory or after market wheels, LeMans stripes)
6. color (preferred white and would consider all colors)
No matter what color Shelby was for sale, if it wasn't a convertible with a 4-speed, I moved on. I knew I needed to be flexible, otherwise I might not ever own another Shelby, after I sold 6S2295. When I found a convertible with a 4-speed it also had a 428, A/C, and was white. Realizing that the car I found was as close to my shopping list as I was likely to find, I sealed the deal. Had it been any other color, I would have likely bought and used it until I found the Shelby I wanted. If the paint was in good shape, I'd keep it that color. If it needed a repaint, I might have painted it white, door jambs and trunk included.
I doubt I would have bought a '68, '69, or '70 GT350 convertible with an automatic, unless it had a special paint color and desirable options. If I did, it would be a car that could tide me over till I found what I was looking for.
Back in 1976, when I bought my car, Shelbys were more affordable and available, relative to today's prices and inventory, so I could be a little more choosy. Today's market conditions call for much more selection criteria flexibility, and I think that's what I'm learning from this thread.
Steve