Riven's designer probably was listening to this song when he worked on her appearance
This is a pretty old song, ( 11 years old! ) and the singer's hair exactly looks like Riven's. So I assume the designer was listening to this song and the singer inspired him/her to create Riven's appearance. :) https://preview.ibb.co/c8DC7x/rivennn.jpg https://www.youtube.com/watch?v=lrtgBsGRpAM