To follow up on that, if you want to do a good job dyeing your hair rainbow colors cheaply and at home, here's my tips:

Shopping list:
1 blonde hair dye kit, the cheapest brand in the lightest color they have- yes even if you already have blond hair, the bleaching makes the hair more porous, not just lighter
2 semipermanent hair dyes in complementary colors. I use Splat because you can get it at grocery stores here. Pick dark/saturated colors; they have more actual pigment, you can use less if you want a pastel shade.
Vaseline and plastic gloves if you don't already have some.
A sacrificial button-up shirt to keep dye off your neck, back, and chest

Steps:
Make sure you don't need to leave the house for about 2.5 hours!
Put on your hair-dyeing shirt.
Use the bleach blond kit as directed, except do NOT use the conditioner packet if it has one. (About 1 hour)
Blow dry your hair.
Apply the Vaseline (thickly!) to your hairline and ears. It keeps the dye from staining them.
Get a clean damp washcloth ready for dye mistakes.
Open the colored dye packages and put the gloves on if it came with any.
Start applying the color in sections. Don't worry about keeping the dye off your scalp, it's a lost cause. Just don't let your wet goopy dye-covered hair touch your face. Wipe it off quick if you do an oopsie!!
To do the back, work by feel and scrunch the hair together to wet it all.
If your hair is long, pile it on top your head and squeeze a bit more dye on it to slick it down so it stays put.
Take the gloves off (carefully!)
Wait an hour. Watch TV, read a book, etc. being mindful of your hair.
Put on gloves again. Rinse your hair under the faucet or even better a removable shower head. Don't let the dye water run over your face or down your body, it will stain! Repeat, you are NOT standing in the shower to do this.
When the water runs clean, towel your hair (with a dark colored towel) and then blow dry again.
Taaaa-daaah!
#diy #hair