I'm finally dying my hair dark blue next Wednesday. Since it's my first time, could someone please give me a little advise?

I have naturally light blond hair (not the yellow type, rather greyish) and I really don't want to bleach it. I never dyed it before (if I don't count going bright orange with Henna couple of years ago), it's middle-length and quite healthy.
How big are my chances to get nice deep blue and how long am I to expect it to last without the bleaching? I heared it might help to wash my hair with harsh soap several times to open up the hair structure and make it last longer. Is it true?

I bought Midnight blue Directions dye and now I fear it might become grey. :/ Shouldn't I rather mix it with a deeper, bluer tone?
Thanks a lot...

Hmmm...
I think this article will explain everything, check it out:
http://haircrazy.info/beginnerguides/dyeing-unbleached-hair/
And when in doubt, always do a strand test first.
Oh and it's always best to wash your hair with a clarifying shampoo before applying something like Manic Panic.
Then the dye will stick to it better.

Thanks...
I think I will just do it and hope for the best. :)
I'm not sure where to get a clarifying shampoo around here (apart from the net), I doubt I'd find it in regular shops. Maybe the soap will have to do.

Most brands have a clarifying shampoo available.
What do you normally use to wash your hair?

Well... I mostly use Pantene or Head&Shoulders.
I never came ocross a clarifying one... But I will try to look harder.

Pantene offers this:
http://www.pantene.com/jsp/product/index.jsp?pdId=111
I've used it before, it was okay.
As for Head & Shoulders, it seems like a few of them could work as a clarifying shampoo.
But there's a quiz that will narrow it down for you:
http://www.headandshoulders.ca/en_CA/product_selector/default.jsp
Just be sure to specify that your hair is oily since you want to remove buildup.
Hope that helps!

Thanks a lot... I think'll try the Head & Shoulders one.

If you have naturally light hair, I would step away from the clarrifying shampoo. Becasue the clarrifying shampoo is used to get semi-permanent color like SFX, Manic Panic, Directions, Goldwell, etc. out of the hair faster than a normal/regular shampoo. The hair described is perfect for any semi-premanent color like described previously, and wish I was born with beige-blonde hair instead of brown.

Dying tips please check out this site. Other suggestions is line the area around the edge of the hair with vaseline to prevent scalp staining. After using a conditioner wait minimum two days, becasue conditioner will block and oprevent the color from staining/dying the hair. Waiting two days will let your natural oils and perspiration to remove some/most of the conditioner. leave on the hair for one hour. After applying the dye, comb hair through with a wide tooth comb to ensure even and thorough coverage of the dark blue dye. After 30 minutes sprtiz/spray/apply on a little water to remoisturize the dye and then rework the dye into the hair. After rinsing the dye until a light blue or semi-clear, lightly shampoo with your ususal shampoo. These are a few suggestions.

Good luck and have fun.

I did it! :)
I used baking soda before and lemon juice after. And I left the dye on for 3 hours. Worked great...
The result is marvelous! Each strand has a different color from dark blue to pool-like greenish shades.
So... Thanks, everybody. :)

The colours you got sound nice! Maybe you can post a picture of the result.^_^