Neon

/ˈnēˌän/

adjective
extremely bright, fluorescent (often used to describe certain colors)

Neon green is a color that demands attention…it’s bright, bold, and energizing.
– Adobe

noun
1. a gaseous element of the noble gas group often used in fluorescent lights and signs

The largest use of neon is in making the ubiquitous ‘neon signs’ for advertising. In a vacuum discharge tube neon glows a reddish orange colour. Only the red signs actually contain pure neon.
– Royal Society of Chemistry

2. fluorescent lighting or signs, often containing the element neon

The world, although well-lighted with fluorescents and incandescent bulbs and neon, is still full of odd dark corners and unsettling nooks and crannies.
– from Firestarter, by Stephen King (1947 – )