I have in my possession a “rainbow error” Dragonair from the 1st edition of the base set. I remember seeing one a while ago on eBay but can now find no documentation on the card. For those who aren’t familiar, the error is a printing defect in the word “number” in Dragonair’s slam attack. I’ve linked some pictures below.
Great question, I’m wondering the same thing! That’s how it was described in that listing I saw on eBay. Wish I had saved a link to that listing because it no longer shows up under completed searches.
How that ended listing managed a 10 on a card that is clearly missing part of the text I can’t fathom, but it’s an interesting error nonetheless *goes to check my dragonairs*