So this is what I used to get my hair this shade of red which I love.
And just as an F.Y.I, I did not dye my hair this colour because of Rihanna. I specifically waited until she dyed her hair a different colour. I don't even like her...well she's ok and her music is very good but she wouldn't be my fashion/style/beauty icon!
I enjoy having red hair because I like to have an interesting hair colour. I love dark hair and I sometimes get temptations to dye my hair dark again but I feel it's too boring and also very hard to change when you get sick of it! I can't be blonde over all the dyes built up in my hair (and it doesn't suit me that well either) so red was my only other option really and I LOVE it :) I can imagine myself staying this colour for a long time!
If you want it, just go for it! You can always change it if you don't like it :)
P.S: Be extremely careful when using bleach!!