Something something red dun.

[sariaru]

http://www.horseworldonline.net/horse/profile/45574

Chestnut base, obvious dun, but why is he this weird grey-ish colour? Pearl?

[Nate]

Strong dun. It's possible he's sooty, turning his base chestnut very close to black on his body, then the dun on top makes him look grullo.

[Argent]

Flaxen sooty red dun

[sariaru]

http://www.horseworldonline.net/horse/profile/104138

Is his daughter the same colour? And, just so I know, flaxen does to chestnut what silver does to black, right?

And what would the genotype for this colour be? (ee/aa?/ff/nSTY/Dd)? Goodness, that's a lot.

[Aela]

Flaxen and silver is not quite the same. Flaxen has no impact on body, whereas silver is a direct dilution gene (as far as I know at least)

I think the filly is silver bay dun - almost looks grullo, but her muzzle looks bay

[nyraeia]

No, the daughter is silver bay dun. Can you see the black tips on her ears? This means she's bay.
About the Flaxen gene: Kind of. It lightens mane and tail and sometimes lower legs + feathers on chestnut and chestnut based horses.

[sariaru]

Oh, I thought the red muzzle meant she was chestnut! Thanks!