So after a winter of letting it grow out unmolested, I went back in today to try a last time. Entirely new brand of color, along with this odd "amplifier"/temporary color from the UK that brightened up whatever color was already in.
I have now got some SCREAMING BRIGHT RED rock-star stripes going the full length of my hair, and the rest of it is a deep chocolate that is almost black. It's brighter than it ever was before. I look like a black widow, and it's AWESOME. I'm spending the evening swishing it back and forth happily like a shampoo commercial.
It's the little things, really. ^_^