Your correct. Anything other than tan, black and the celery/white is a machine that has been painted. Usually they are the black ones that have so many blemishes on them or un-usable as they are that repair guys/gals will recondition them and then repaint in glorious colors all dressed up with new decals. Some will tell you that it downgrades them but try to find a colored one that is equal $$'s to or less than an original 221. Not possible. If you ever follow them on ebay, you will see that the colored are in the 700-800 range verses the normal ones at 300-450. My blacks were from 200-350. My white one was 550. Don't even ask what the free arm 222 was. Even my husband doesn't know, not that he really cares.
I have one that had lots of missing pieces and is in the process of getting new/used parts. When I get it back, it will be shipped to a guy that will paint it red for me. He has a website showing many he's already done. So I'll send it to him.