Made famous by orange signs a century ago, little of the gas is actually employed today in lighting having been replaced instead by colored fluorescent lighting and, more recently, by LEDs. Still, say neon sign and everyone will think of a shop sign with words made of lit up glass tubing. You can, to be sure, still find the old fashioned neon signs for a (pricey) retro look that no cheap LED can replicate.
This small amount of neon gas won't light up but it is the real deal and won't cost you much. Comes in semi-hard gel in 25mm box.
This gas ampule containing 99.9% pure neon gas will glow when ionized under high voltage. See colors at bottom of elements page