David Heyman recently spoke to EW and discussed the role of young Dumbledore which will be portrayed by Jude Law.
This younger Albus Dumbledore’s long hair and beard were auburn. Having reached their side of the street, he strode off along the pavement, drawing many curious glances due to the flamboyantly cut suit of plum velvet that he was wearing.
One of the reasons we chose Jude is he has many of the qualities we find in Dumbeldore in the Potter films. He’s got authority, he’s got a twinkle in his eye, he’s sometimes a bit elliptical. So you have that but also have this youthful energy and jubilance. So he brings that twinkle, mischief, authority, and power, but at the same time brings far more youthful energy to the film. You understand why he would be your favorite teacher and be someone you believe is an extraordinary wizard.