Welcome! I’ve been on a similar hunt that has spanned since the series began. I’m 13 books short of a full run in 9.8 (I include the three editions of #38, Rose, Rat Tails, and all the one-offs as part of the run).
I’ve never really cared about the multiple printings except for the Image books that have different cover art (just have two of those SS’d) so I can’t help you with a list of which colored “Bone” title corresponds with what printing.
#12 has three printings? I’ve seen a blue title for what I thought was the second print but haven’t seen another variation. Please show if you can.
Good luck!