I'm discussing writing with some of my friends, and I recall reading something as a teenager: it was about a guy who's a Dragonlord? I think, who has a reddish blotch on his face that reflects the color of his scales when he turns into a dragon (a process brilliantly called "Change," with the caveat that anyone who sticks him with iron as he transforms can totally kill him). He goes to a political conference to help settle a succession, and ends up with a lady sea-captain with one blue and one green eye, who turns out to be his "soultwin" and also a dragon-person. It seemed cool at the time, but everything I remember is fairly meh...but now it's really bugging me. I thought it might be something by Melanie Rawn, but none of the books on her Wiki page match at all.