To me the Union symbol looks like someone (the brown/orange part) cowering in front of a warrior-figure (the green maskish part.) Cardassia WILL crush it's enemies and they know it. And so do their enemies. Fits the Cardassian Union's personality But I like everyone's theories.
I love Cardassians. They're also my six-year old brother's favorite species. I don't think I could even have said
'Cardassian' when I was six...but I digress.
I'm sure Cardassian blood is red. And I've always been baffled by the apparent ease with which different Trek species interbreed, it certainly shouldn't be possible. On the other hand...if they all were originated by the same Progenitor, I guess the different DNA's ability to decide what traits to take from what parent would be part of the 'programming', which seems no more difficult than forcing the galaxy's inhabitants to all smile and kiss with their mouths and walk upright and like pretty colors. And that's an interesting point about Spock's birth.