Black light chalk - the chalker's "magic wand"

Black light (or "invisible") chalk is mostly used to create hidden pictures of a person or object which later becomes visible under fluorescent black light. Although, this subject has been well covered in a number of publications, there is still room for discussion here.

What has not been so well covered is the use of black light chalk to create other effects. For instance, it's possible to turn a winter scene into a spring scene by creating white snow which transforms into green grass. Or how about a pillar of cloud which morphs into a pillar of fire.

Hmmmm...what can you add to this discussion?

Best,
Kerry