As you may know, there is some controversy about the casting of a Black actor to play the part of Hermione, which has led, among other things, to questions such as "Was JK Rowling involved with Noma Dumezweni's casting as Hermione Granger in Cursed Child?" and "What is Hermione Granger's ethnicity?"
Given that supposedly Rowling never definitively stated Hermione was Caucasian in the books, I'm wondering for which characters she did explicitly state a skin tone or race. If I recall correctly, Dean Thomas was originally described as a "black boy", but I'm having trouble thinking if there were any others. Were any characters definitively stated to be Caucasian? Was Cho Chang even explicitly stated to be Asian (her last name being an indicator, of course, but not definitive proof)?
Please note I am referring to the books only. The fact that Shefali Chowdhury and Afshan Azad were cast as the Patil sisters in the films does not indicate anything about the characters' origins in the books, for example.