That's a really good idea, Happy Ending, but you can also just take an old damp washcloth and simply wipe the color that's on your skin off once you apply the color to your hair if you don't want to fiddle with tape or mess with the petroleum jelly.
JustPlainJo, actually that pink tape was used for keeping the old fashioned metal clips used for hair rollers and/or used for making pin curls and waves from burning skin where they might be touching ears and hairline when you sat under the hot hair dryers of old while drying. Once the hair paper called San-ex came out it was used instead. Not only was I a hairstylist for 35 years but so was my mom for that many years. I was in her womb when she was in Beauty School and worked on Saturday's in her salon when I was 12 and 13 helping remove those rollers for all of the stylists, sweeping hair, getting coffee for the clients, etc. :-)