[1985 CCX]

Dow #7 is Dichromate Treatment on Magnesium (This is the gold tint!)

A study was made for the Army Aviation Materiel Readiness Command to evaluate the effects of various surface treatments and corrosion resistant coating systems on the fatigue properties of three send cast magnesium alloys (AZ91-T6, ZE41-T5, and EZ33-T5) of current or potential use in helicopter component housings. This was part of a larger program undertaken by the Frankford Arsenal to provide significant reduction of costs and downtime associated with the corrosion degradation of these housings. Coatings evaluated were DOW 1 and DOW 7 chromate conversion coatings and the HAE and DOW 17 anodic coatings, both light and heavy applications. Pretreatments such as acid pickling, shot peening, and polystyrene impregnation were also evaluated as well as several different organic topcoats

From Rod & Custom website from 34 Ford restoration:
The 34 rolling stock matches the performance theme with a set of pure magnesium rims custom cast by Ron Blondell to perfectly match a set of super rare Halibrand hoops used on mid-'60s Watson Indy roadsters. The rims are coated in the same Dow 7 coating used to preserve the original rims, and that's what gives them that classic greenish gold tint.