I need some tips about dying hair.

[Aerobe]

You do not provide the salon with color.
Most salons WILL NOT use color you provide as they may not have a MSDS sheet on it.
They will be held liable for anything that goes wrong. So if you somehow get a chemical burn - they will get in serious trouble for using a product without having the MSDS sheet and other important information.

You can however talk to a stylist and see if they can get the color you want from the lines they carry or if they can order you a color from that brand.
Not all salons carry the full color line from a company. They should, but what's the point of spending hundreds of dollars on a color that next to no one uses?

[Ardeverci_xCloette]

Here are some tips:

-DO NOT DYE YOUR HAIR IMMEDIATELY AFTER BLEACHING or ON THE SAME DAY.
scalp damage from bleach job is horrible, and if you dye your hair right away when your hair's not been completely dried yet (it may look dry, but it might still be wet inside!), the dye will NOT SHOW UP AT ALL, and you'll be dying to scratch your head since it will be itchy. VERY. Itchy.
-DO NOT DIG THE COMB LOCATED ON THE DYE BOTTLE INTO YOUR HEAD!
Again, scalp damage. It will hurt and itch at the same time. Just brush the comb through your hair and use your hand to apply the leftovers.
-USE CONDITIONERS
If not, you'll have your hair splitting in all directions, driving you nuts. Try hair masks since you only have to use it once a week. It's really moisturizing.

L'oreal Paris Sublime Mousse

I usually use Palty if there's a specific color I want, but Mousse types are the easiest to use these days. You can actually dye your hair alone with those!

[bebeparanoia]

you're gonna have to bleach it anyways if you want it white/grey. It's gonna be even much harsher than blonde...