Here are the photos I took of the four chins at the MCBA Shindig this past August. Two are Lowe Recessive Whites bred by Pam Snider of Alderbrook Chinchillas. One is a Goldbar bred by Paul K whose lines go back to Serena's at Chinchilla Park Place. The other is a Goldbar bred by Jim Ritterspach directly out of Bob and June Baar's lines.
Pretty much everyone at the Shindig thought they were the same. The attendees were experienced judges, long time breeders, and heavily involved enthusiasts. There were no fly-by-night breaders there.
Statistically, it is very improbable - after having gone over 40 years without a new color mutation - for the next two to pop up within a couple years of each other, in roughly the same geographical area (western north america), and look this similar in appearance. Again, statistically, it is more likely it is the same mutation that was carried for several generations, eventually surfacing on two different ranches, and the (slight) difference in appearance (for those that can pick it out) accounted for by the different developmental goals of those ranches.
However... At the shindig, Jim said the goldbars are born looking like pink whites and later darken. Pam has said the LRWs are born with a golden hue and later lighten up. Pam also said the LRWs produced more males than females, and Paul has said he had an overabundance of goldbar females and not enough males. So maybe the statistics lie in this case, and it's just coincidence they look the same.