Donald is drawn to resemble his original appearance. He wears his ordinary clothing including a blue shirt, a red tie, and a blue sailor hat.
Donald Duck can be quick-tempered when things don’t go the way he wants, but he has a heart of gold and is very devoted to his friends.
In the season 2 episode Down the Hatch, he sings like a rockstar instead of producing his characteristic 'quacking' voice. This also happened in season 3's Split Decision, only he had a non-angered voice.
"And it's all thanks to you, Mick!" — Donald[source]