According to Vintage Guitar Magazine's Price Guide (2008 ed):
The Mustang first came out in 1964.
Fender Mustang (64-65) in Excellent Condition: Daphne Blue (unfaded). : Low $1,650. High $2,200.; Dakota Red or Olympic White: Low: $1,525. High: $2,100.

Those were the only 3 finish options until 1969. So if that natural one in the photo, if a '64-68, had the original finish stripped off.