Just want to "weigh-in" on this subject (color), several points;
1) My car is a 1970 (Aug '69 build, Dearborn) with a FMX, (351W) and the trans is original to car (VIN stamped). The auto dipstick tube was painted turquoise. I found Ironlak brand, Gloss Acrylic Spray Paint (rattle can), Iceberg/Light Turquoise as a perfect match. I found this at an area Hobby Lobby. (SKU# 334670 000703)
2) the MCA Rules for 1969 - 1970 Concours Trailered/Driven ('22 revision), call for the tube finish to be "Black Finish" with two exceptions for 428's. I've been questioned by judges but haven't had points deducted (yet). My point here is for MCA to review this and (hopefully) be in line with what appears to be a missing detail in the rules. I put back my car's details as I found them (within reason due previous owners changes) but I've known restorers that use the MCA rules for these details and I can see where a turquoise color becomes black to comply with the rules.
Thanks Big Al