Retro Donald

Donald transforms into his original version of the earlier Disney cartoons when he visits Timeless River with Sora and Goofy. In this form, Donald is called Retro Donald.

Donald's classic look seen here, is largely unchanged from his modern appearance. As the Journal states, his first appearance was in 1934's The Wise Little Hen, though by that time, the Disney shorts were already rendered in color.

In this form, he is able to use all the kinds of magic and fighting skills he previously learned during the game.

Kingdom Hearts II
The Wise Little Hen (1934)

The Royal Court Magician.

To save Disney Castle, Donald went through a doorway Merlin conjured up into a black-and-white world that seemed strangely familiar.

Appearance
In his Retro Form, Donald transforms into a monochromatic version of his original appearance in Disney cartoons. His shirt is black and the buttons, bowtie, collar, and stripes on it are white. His beak is grey and longer than it is in his normal form. His feathers are completely white, white his legs are black. Donald's eyes are large and simplified, and he wears his sailor hat—now white with a black rim and tassel—on the top of his head.

Donald (Rétro)