I'm feeling the need to reiterate this from my first post, since it is so long:

Now, before I go into what I did and how I did it, a few things to keep in mind:
  • This is NOT A HENNA REMOVAL METHOD. You are not going to get back to blond with this.
  • This method worked for me, and may work for someone else, to lighten up henna a few shades. Do NOT expect it to make you a copper redhead if your natural hair is dark brown or black. You can't go that far without damage.
  • I did an assload of strand testing and went very slowly, doing this over the course of two months. If you decide to try this, speed things up or skip steps at your own peril. I don't want to hear, " Nightshade I nuked my hair trying this, but I didn't strand test and used a whole bottle of Sun-In on dry hair, hit it with a hair dryer and then went tanning on the beach for 10 hours." I'm joking here, but only in part.
Really, I'm not joking at all.

BE SMART PLEASE! Strand test and TAKE YOUR TIME.