Looks like a grey, also called mallard coloring... are you sure she is a Muscovy? I don't have a lot of experience with 'scovies, but she doesn't look like a typical 'scovy to me... can you get full on pic of her face and bill?
Also, just wanted to say I think Amiga nailed it dead on... she was terrified, not aggressive... we don't think about it as much as we should, but ducks know instinctively they are a prey animal... hands coming down mimics winged predators to them, and if something was harassing them at that farm, she was acting out of pure fear and instinct... the others now picking on her actually supports that as well... they would avoid her more if she was really aggressive...
Fear is the most powerful driving force in an animal... and it can escalate to being much more dangerous than just aggression... there is no way to predict how an animal will act in the grip of blinding fear...
Sounds like you are doing really well working with her... I'd like to suggest some tips if you need them or can use them... if possible either elevate their brooder so your approach helps them focus on your face first, or make sure they have a side access into the brooder instead of coming down from above... when reaching for her, keep your hands low and go up under her breast first rather than over her back... keep movements slower and steady around her, don't move fast or jerky... it takes a lot of time to earn trust, especially if there was trauma in her past... just be careful of yourself as well... they can cause some severe injuries...
Also, just wanted to say I think Amiga nailed it dead on... she was terrified, not aggressive... we don't think about it as much as we should, but ducks know instinctively they are a prey animal... hands coming down mimics winged predators to them, and if something was harassing them at that farm, she was acting out of pure fear and instinct... the others now picking on her actually supports that as well... they would avoid her more if she was really aggressive...
Fear is the most powerful driving force in an animal... and it can escalate to being much more dangerous than just aggression... there is no way to predict how an animal will act in the grip of blinding fear...
Sounds like you are doing really well working with her... I'd like to suggest some tips if you need them or can use them... if possible either elevate their brooder so your approach helps them focus on your face first, or make sure they have a side access into the brooder instead of coming down from above... when reaching for her, keep your hands low and go up under her breast first rather than over her back... keep movements slower and steady around her, don't move fast or jerky... it takes a lot of time to earn trust, especially if there was trauma in her past... just be careful of yourself as well... they can cause some severe injuries...