Where can I find this hair?

Her hair color is just...red. She has probably gotten it done professionally, Since Rihanna's hair is naturally a dark color it would had to have been bleached. You could bring that picture in to a stylist, show them them, and tell them you want her color. Or, if you're short on money you can get "Splat" hair dye, Luscious Raspberries, for $9.99 at pretty much every Walgreens or Riteaid Stores. i do not think Walmart, Target, or Any food store sells "Splat." i hope you find your color! good luck:)