I was supposed to get base color/ light brown with highlights. Way too dark, how do I lighten or get it to fade - fast

This happened to me once before.I used a little lemon juice(real lemon juice,not the sugar loaded king) with conditioner and it helped bring the color about one to two shades lighter.Results can be seen after one to two uses.

ColorFix, Color Zap, Color Oops will all remove the color so you can get another shade and re-dye it. Lemon juice is a very poor choice (hair damage). Clarifying shampoos will cause it to fade a bit faster.