Read over the instructions on your Splat kit first so you know the time frame of the steps.
Perform an allergy test the day before you want to dye to make sure Splat won't irritate your skin. Clean your forearm with soapy water, then pat it dry. Apply a couple drops of dye and let the dye soak in for 24 hours. Clean your arm the next day. If your skin itches, burns or gets inflamed, you are allergic to the dye and should not use Splat products.
Cover your hairline with petroleum jelly to protect your skin from the dye.
Bleach your hair beforehand if it's dark or if you want to get vivid color. To bleach, open the "Splat Oxide" bottle and pour in the contents of the "Splat Lightening Bleach." Re-cap the bottle and shake it for a good minute. Swap out the cap for the applicator tip. Check the bleach chart to determine a time frame for your locks. Once you know how long to dye, apply the bleach using the applicator, saturating 1/4-inch from your scalp. Cover the bleach with a shower cap, and check on its progress every 10 minutes. Rinse out the bleach at the end of the time frame and shampoo your hair. Dry your hair and apply more petroleum jelly to be ready to dye.
Shake your bottle of Splat color to distribute the dye evenly. Again, swap out the cap for an applicator cap.
Squeeze the Splat onto your scalp, saturating the area you want to dye. Again, don't get closer than 1/4 inch to the scalp. If you spill dye on your skin or the floor while you are working, wipe it up because that dye will stain.
Keep the Splat on your head for the recommended wait time -- again, use the color timing chart -- and again cover up with a shower cap.
Rinse out the dye in the shower. Splat is concentrated color, so keep rinsing until the water runs absolutely clear. If you don't get it all out, you risk staining your pillow.
Shampoo your hair post-dye and rinse again.
Dry your hair completely before going to bed.