Re: need help
Ideally, you should get a professional to change your hair colour from dark brown to red.
If you want just a reddish hue, then you can use a glaze or something like Manic Panic, which might not work but aren't harmful to your hair. Both are temporary.
To do it at home is somewhat risky, because you do need to lighten your hair. Since its dark, you need to bleach your hair first. Then you can use a red dye, but I don't personally recommend this. You could end up with orange hair, or even greenish. If you want it temporarily a bright red and don't mind spending the money every few weeks, then bleach your hair and use Manic Panic as you desire, they have a lot of colours. Since your hair is dark, you might need to bleach it a second time or leave it in quite a long time to get it light enough - your hair will be damaged, and you should not spare any cost to get a great conditioner and a hair mask ( and a daily conditioning spray! ).