I have naturally dark auburn hair, but I've dyed a soft black, which I like. However, I moved to China and I'm having trouble maintaining my color. My Mandarin is limited, so I don't want to go to a salon and I'm really limited on boxed hair dyes. My roots are growing, but is there a way to fade (as healthy as possible) my current color and then I could dye it (with a boxed color sent to me from the States) back to my natural red color?

Would tomato juice fade it? I heard lemon juice does, but I can't find lemon juice here. I also haven't seen Prell.

Lemon juice and water in a spray bottle does work. Have you tried one of the street markets? I lived in China for two years and know the "pain" of trying to find common things in the markets.

You could go with the whole "literal" pinyin translation:
Wo - I
You - want
Huang - yellow
Tou fa - hair

Or

Wo you tou fa ran ("ran" in third tone). That's " I want hair dye."

... but I'm not sure I'd recommend that.

Have you tried a Carefour? They sometimes have imported products and/or products that are Chinese, but you might be able to find someone that speaks enough English.

Or, if you're brave, find one of the young Chinese students who have dyed their hair and ask what they used. My students typically used bleach or peroxide, which you wouldn't want to use, but you never know!

Best of luck! In the dye AND the Chinese experience! Enjoy it - its wonderfuL!