In a word, no. Starting as early as SA-10 in 1965 there exist “trial proofs” in alternate colors. While they may have been struck to determine which color to use it is more likely they are philatelic favors done by Forrest Rhodes at the KSC post office for friends or to supplement his income.

Alternate colors are often seen in tandem with legitimate ONCs. When seen with Cape Canaveral hand cancels the postmark may be     backdated. When colors appear in alternate sized artwork the cachet is commercial.

While the KSC Official is issued in blue or red (or black in the case of Helios), there are apparently legitimate examples of some Apollo ONCs in blue-black or definitely black. These should be regarded as simply having a different ink pad and not either illegitimate nor an entirely different ONC.

The number of rubber stamps used to create impressions is unknown. Applications ranged from as little as 500 for Open House in 1970 to 166,650 for Apollo 11 in 1969. In the only example which has come to light, the Post Office revealed that two rubber stamps were created to support the 1400 Helios impressions made in 1974.

Some impressions over the decade were consistently superior. Apollo 10, for example, almost always looks great as does the machine cancel. Others, like the blob also known as Apollo 12, almost never looks good. This can, in some part be explained by the design. Apollo 12 is very subtle and might not have expected to reproduce well. It was just such a concern that prompted officials with the Post Office to ditch the engraved designs for AP-7 and AP-8 and substitute labels.

In some instances, notably with Gemini-VIII, there is excessive wear. While the number of impressions, 12,370, was large, it dis not approach that of GT-XI (17,790), GT-XII (18,500) or AS-501 (34,000) which looked much better. While there are some proof-like impressions of AP-11, the vast majority were not very worn (although usually light in color). How many devices were produced and is there any variation in their usage?