My '69 Barracuda 340 assembled at Hamtramck early November 1968 had unpainted springs. Dart 383s could have been assembled at Hamtramck but had different springs part number wise.

I found black paint on my spring assemblies but later realized it must have been painted by a spring shop where I had an extra leaf installed years ago. The tipoff was black paint on top of and not under the latex markings near the front eye.

Look very carefully for factory latex paint daubs near the front eye from about 9:00 to 12:00 on the left spring (12:00 to 3:00 on the right), and you might find remnants, as that area is mostly protected from road debris and weathering.

My colors were khaki and aqua, but yours should be different.