How do you color already colored reddish brown hair to make it a bright red color?

you have to strip it so that the fire engine red will not be darker than you want it to be

How do you color already colored reddish brown hair to make it a bright red color?

i dye my hair A LOT and ive noticed bright red is the hardest color to get and even harder to keep from fading. if you are serious about it you should really go to a hair dresser. there is a lot of room for error. if you are brave enough to do it on your own go to a beauty supply store and buy a lightener, it will bring your hair to a color that will make the bright red show up. then dye. good luck

How do you color already colored reddish brown hair to make it a bright red color?

You need to bleach your hair. I use Clairol BW2 with 30 volume liquid developer. I use liquid developer because it gives better coverage of the hair, the creme developers tend to go on too thick. Then you need a good semi-permanent hair dye like Special Effects. Stay away from color that has orange undertones unless you wanna look like Ronald McDonald. IMO Special Effect Candy Apple Red is a good deep, rich red. That's the one i've used and liked best.