I already have red hair, but I want to go FIRE engine red! My appt. is tomorrow so I need to go to the store in the AM!

[pseudorocknroll]

I don't want it to be pinkey or orangey at ALL. I want it PURE FIRE RED. What color of Special FX would be perfect for this?! I have a hair appointment TOMORROW so I want to stop by the store before the appointment- so any kind of advice would be amazing!!!!