My cat was an absolute aloof biter bastard (dark tortie too, never knew that about them!), I thought it was because she was dragged up, she was greasy and filthy, in a stinking house, when I paid a fiver for her. That fiver still rankles!
Then she got herself lost. We had moved, and I kept her in for a month, she went out happily for a month, then she was gone.
I'd given her up for dead after pestering the council and leafletting the area for weeks. She was finally let in and fed by some cat-loving people, a mile away from me, in the direction of our old house. They read her tag and rang me and I got her back, she was starved and weak, wobbly weak, poor girl. She's only got one eye so is a piss-poor hunter, unless it's baby mice.
Ever since then she's been a lovely diamond cat, comes for a stroke, sits on your knee and bites no more.
So what you need to do is lose then for a bit and then they'll turn nice 