Matty B, an 11-year-old rapper, is winning praise and scoring millions of YouTube hits with his new video that defends his younger sister who has Down syndrome.The young rapper and his family came up with the idea as a way to empower 8-year-old Sarah.The video, derived from the Cyndi Lauper hit "True Colors," shows a dramatized situation in which Sarah is spurned by her peers but eventually wins them over."Some people at school might pick on her for her needs, but I don't think anybody should be bullied because of what they have," Matty said."It's really so special to see Matt and Sarah interact. Sarah Grace loves acting, to be in front of the camera. She was very excited," mother Tawny Morris said.The video has racked up nearly four million views on YouTube.Matty hopes the video will inspire other kids with special needs and teach them they can do anything.