Ron is ginger. So white. Harry has bright green eyes. We know his mum was white (ginger hair, green eyes) and his dad is never described in much detail, but I think has hazel eyes. Hermione is described as having a "white face" at one point, so also white.
There are definitely issues with making Hermione black, as in the cursed child plays, because of the mudblood slur.
Draco is possible, but again is described as pale a lot, but the Malfoys are pretty awful people -would they want to colour swap any of the "baddies" to non-white characters?