Tips on how to apply hair dye to already dyed hair?

I have dyed my hair with permanent red/brown color a few months ago, and now my dark roots are showing. I want to change the color to a deeper red, a shade or two darker then the dyed hair I have now. I was wondering, what is the best way to apply the new hair dye to my hair - roots first and then ends later with a shorter processing time; or ends first and roots last with a shorter processing time? I am afraid that the color will not be even, and am not sure if i should dye the whole head again as you would to virgin hair. thanks.

Tips on how to apply hair dye to already dyed hair?

30 days what are you talking about? Ok you're going darker thats no problem apply to your roots first then in the last 15 pull through to your ends. Remember going darker is easy going lighter is a pain in the butt! color will not lift color so you will have to lighten if you get sick of dark!

Tips on how to apply hair dye to already dyed hair?

Gotta Wait 30 Days After You Dye It.

Tips on how to apply hair dye to already dyed hair?

you dont have to wait 30 days. maybe one week, just so you dont dry out your hair. all you have to do is try a darker red color dye. i always dye over my hair. its easier to go dark to dark, than trying to lighten your hair. right now iam have the probelms of trying to lighten my hair. just make sure you use a good conditioner and also when i tryed to darken my brown hair to a nice dark reddish brown, maybe try having the dye on your head for only 15 minutes not the 25min. that some ask for. it might get so dark that you only see the reddish in the sun only. i hope i helped you...

Tips on how to apply hair dye to already dyed hair?

you need to get in there now and do the head since you are changing colors, got to do the whole thing when you change colors