I striped one of my helmets a few years ago on a whim and can say that the stripe has held up well, hasn't faded or anything like that. I haven't taken it off so no idea how it looks underneath. Mine is navy and red and silver so it's patriotic but not crazy, I still kinda like the way it looks lol!
I striped my GPA pink and white for a horse show for breast cancer research. A year later I removed the pink stripe and left the white. The stripe came off no problem and about 6 years later the white stripe is still on it.
Live in the sunshine.
Swim in the sea.
Drink the wild air.