i dyed my klippan cover, however mine was already a unbleached natural color. so i would definitely recommend a color remover first, and i would do it in the washing machine. i don't know if i would recommend a choc. brown color though, b/c that is what i tried, and i could never get it to look brown, the color was even , but always looked more purple than anything, after 3 times though i just gave up and settled for a funky purple/brown.
the funny thing is, I'm buying another klippan cover so i can dye it that green color that your cover is, go figure.