"Luminous colour" refers to a color that is very bright or radiant, like the glowing light from a bright bulb or a vibrant neon sign. It stands out and catches your attention because it appears to emit light. Full definition
This translucent wash of luminous colour can be swept all over the face for a lit - from - within glow. (debenhams.com)
Spray paint, I think luminous colours work well I used neon pink, but you can't actually see how bright it is in the pics for some reason? (lazydaisyjones.com)
It's a public art, an art of luminous colour, an art of wild imagination. (independent.co.uk)