Probably wrong as the Misses always points out, but............, of the original cars we have had they have black painted spares. I do believe this was the case as it would have been a PITA to supply spares that were stocked to match the rim color callout. Especially when one thinks back to the day if they were color keyed you could have the possibility of a yellow spare rim in a red wheel car. Buildsheets were mixed up on over a dozen cars we restored, only a couple digits off, very similar car but wrong sheet.
Anyhow will go check on an original 67 QQ1 Formula S we have had from new tonight.
Then again probably wrong again, though doubt it on this one.