The answer is NO.
The fact of the matter is that racism still very much exists today in the United States. even though it is Halloween, a time to dress up and have fun in costume, be someone other than yourself, portraying black face is unacceptable. Julianne Hough may be an actress and not mean anything immoral by it but there are still many people that will take offense to it. The sad thing is that Julianne could have portrayed a white actress. There are many on the show Orange Is The New Black but she chose to portray the black actress.
The context of the costume will be lost on many because racism still exists. it is still a touchy subject in this country. It would be a perfect world if we could all learn to laugh and joke but the time is not now. Julianna, my message to her is that she should have been more sensitive and known what she was doing.