temporary red dyes are not really so temporary. they're actually quite tenacious. i had a professional bleach my hair after i'd used a semi-permanent red dye and even she couldn't get the white blonde i wanted. my (unprofessional) guess is that you'll get a strawberry or golden blonde.

Try asking your usual hairdresser (or a hairdresser friend) about a color remover. They're pretty harsh, but it may be the only way to strip the red out completely. You may not even have to go to that extreme - I use Manic Panic (Vampire Red), and I can usually remove the red to start over with a fairly low number developer (20 or so) mixed with powdered bleach for a short duration (about 10 minutes).

As for going darker: it will solve your problem in the short run, but if you want to go blonde again in the future you will encounter the same problem - only more so! I know from having tried that myself a couple of years ago. I had to strip my hair so severely to get the brown out that my hair basically turned to straw.

Try washing your hair with either Prell shampoo, or dishwashing liquid- either of these will help pull the extra color out of the hair- but you'll have to use a good conditioner afterwards.

Ok.....

Red is one of the strongest base pigments in the hair and the most difficult to pull out... I can bet many reading this have experimented with dying their hair black and then wanted to go back to a lighter color some want to go blonde... Well that is a hairdressers worst nightmare. Bleach is how the color is stripped and so the cuticle of your hair, if you not careful you have what feels like over cooked spigetti when its wet and cotton after it dries... What you end up with for color usually resembles Gold fish...

Please even if you do not color your hair stay away from astringent shampoos like, Baby shampoo (yes thats right), White rain, Prell, dish detergent there are more but Im drawing a blank this morning..

First try pulling the color out by applying a good quality heavy conditioner and appling heat... wash towel dry and slap in a generous amount of conditioner, massage through comb it, bag it, towel over that and hit it with a hair dryer... Heat it up good all over , let your arm rest, and when it cools down hit again with the hair dryer... I would do it for 30 to 60 mins and rinse.. You will have to repeat but it will help remove some of the red pigment and ready the hair for coloring...

I would shampoo with swimmers shampoo, nexus makes one of the best, designed to get the green out from clorine pools...
use this shampoo every other day for a while. BUT NOT after you have colored it the color you wish,
Try not to be impatient you and your hair will be thankful in the end...
Besure to use a moisterizing conditioner, like humectant, Suave has a fairly nice knock off of it...
Be careful with conditioners that boast about protien, these should be used at the most once a week, the protein has been known to build up and create brittle hair.

8N is reasonable 8 is the level of lifts, N means its nutrual it has equal amounts of each base pigiment, a good choice again..