[Help] Trying to dye my backpack from bright green to brown using Rit Dyes. To make it brown, do I use red, brown, black, or what?

So I purchased a backpack to go traveling, but the honeymoon period with the color is wearing off on me. I read some online tutorials on how to dye nylon, which seems pretty straightforward for black, but f I wanted it to look brown, should I be using a brown dye, or a red dye? I am concerned if I use a brown dye, it will come out diarrhea colored (green-brown), but I am probably even more scared of using red.

I can also try bleaching it first, however, I am hesitant to do so with the nylon considering I may compromise the structural integrity of some components that I can't remove in the backpack, as well as possibly damaging the nylon.

Does anyone have any experience with this? Ideally the color I am looking for is "sand", but I can settle for brown, and should I use red or brown?

This is the pack: http://www.ospreypacks.com/images_products/451_1138_xl.jpg

Thanks in advance