My sister, @mythlandfaerie, just died her hair blue, so I thought i'd do a tutorial on it(;
So, before you begin, you should know NOT to shampoo your hair the day of getting your hair dyed!! It will get rid of your skin's natural oils that protect your scalp from irritation.Also, unless your hair is naturally a very light blonde, you will need to bleach it to a pale yellow, then use a purple toner to turn it white. This will give you the most vibrant color possible.
Dyeing hair is messy , so a few precautions in advance will save you a lot of cleanup time later.
Apply a layer of Vaseline around your hairline, ears, and around your neckline to avoid coloring your skin.
Wear an old button up shirt so you won’t have to pull anything over your head, and won't get anything dirty.
Wrap your shoulders with an old towel(kind of optional)
Wear latex gloves.
Before you actually color it, spritz your hair with water. This will make the color flow through your hair more naturally.
Part your hair in the middle, and then from ear to ear. Clip up each section, and color one section at a time. This will help you avoid missing any spots.
paint the color in from the root to the tip, massaging it into your hair with gloved hands. Work as quickly as you can, but work carefully.
look at the bottle, and follow the instructions on how long to leave the dye in your hair(;
Using cold water, rinse your hair until the water runs clear. If your color kit includes conditioner, you can apply that, but do not wash your hair for at least two days. This gives your cuticles a chance to close, holding your color in.
Wash your hair with cool or cold water. Hot water will allow some color to wash out.
Every 3 or 4 weeks, touch up your roots by first bleaching and toning them as above, and then apply a new coat of dye to refresh your overall color.
I hope this tip helps!! Have fun;P