As Ali said, the gladiolus is a plant noted for being brightly coloured. The author could be using a neology in order to suggest that the foreglimpse was vivid.

It sound good though, you should give it a definition. If it's good, i'll start using it :-P

Not a word!

I don't think it's even a word. Although gladiola is a plant which has a lot of brightly colored flowers.