Purple haze or ultra violet manic panic on unbleached hair?

I dyed my hair a really dark brown, almost black about a month and a half ago, and now it's faded to about a light reddish brown. I want to dye my hair purple, but I'm not sure if I should use Purple Haze or Ultra Violet Manic Panic. Which would show up better? I can't bleach my hair because it's permanent and my mom won't let me.