You're right, the coloring is too light for Rouen. Also, the shape doesn't look right to me for Rouen. I've had Rouens. This one is more elongated, but not as much as a runner. Rouen duckling bodies are sort of rounder and flatter, like a deflated football-shaped patty rather than a tube or bowling pin.
I have been Googling names of duck breeds to see if any of them looked like what I have. The closest I've gotten is Muscovy? Anyone with experience with Muscovies out there? Some of them looked like mine, some didn't:
What does everyone think? Does mine look like this?
It's not a Muscovy, the bill is not right, but if the colors in the picture are correct it probably will be a blue fawn color. It could possibly be a Mule duck(MuscovyX) though.
I don't have a pic up, but that looks exactly like one of my girls from metzer farms, she's a golden 300 hybrid. She's all feathered out now and looks similiar to a mallard but she still has the stripes on her eyes.