Bolt confusion

[jm29henry]

I am starting to detail my engine bay ,and would like it to make it correct as possible . My confusion is when I look in the catalog they state black or zaven are the proper ones for carb and valve cover,timing pin and charge more money. When I check the newest judging standards the appear to be plain unpainted 1- what is correct,2- wondering why more than 1 suppliers state black,or raven ( my car is a Feb 3rd 1929 build date on fire wall) thanks for your help in advance .