Identify breed: Indian runner? Pekin?

[Swanak]

I took in a pair of ducklings a week or less old that were dumped by the river. Someone saw them being left with nothing but a small pile of chick starter. After doing a little searching online I’m pretty sure the dark one is a Rouen but not sure what the lighter one, named Mustard, is. Mustard tends to stand more erect and has a much slimmer long build, but also will hang out in a less upright position. Sweet but more akittish compared to the Rouen. When Mustard walks it’s more upright so I thought possibly an Indian runner? Or a really skinny Pekin? A cross? Would appreciate help identifying.
Attaching some picks. My best guess for the ones in the bathroom are between 2-3 weeks of age.
The ones outside likely 3-4 weeks of age.

 

[Swanak]

When he’s on the move he definitly is standing tall or taller than in these pics.

 

[cheezenkwackers]

I believe you are correct and Mustard is a fawn and white Runner. What did you name the Rouen? I have a duck named Mustard too. . You did good rescuing them!

 

[Swanak]

I believe you are correct and Mustard is a fawn and white Runner. What did you name the Rouen? I have a duck named Mustard too. . You did good rescuing them!

Rouen is Blackberry. My kids named them. Otherwise I would have had some sort of duck pun to make up for all the poop I clean.

 

[Pollo Blanco]

Congratulations and bless your heart, and yes, Mustard is an Indian Runner!

 

[Miss Lydia]

So wonderful that you were able to rescue them. Bless you!