Fluorescence and neons are a form of luminescence. Emitting light through radiation, without heat.
Fluorescent and Neons pigment colours work in an entirely different way than usual pigments.
They are brighter than normal pigments because normal pigments work by subtracting (absorbing and converting to heat) colours from humanly visible white light, while florescent colors work by converting humanly invisible ultraviolet light into humanly visible colours.
So, ordinary pigments make a surface darker and florescent ones make it lighter.
There are slight differences between fluorescent and neons, mainly to do with the radiation process (how the atoms are excited ) and colour discharge.
Fluorescent and neon lamps work are explained very nicely here.