food coloring in a glitter lamp?

[matt]

My girlfriend has a clear liquid/ silver flake glitter lamp ( a cheap one), and she's been thinking it would be nicer with blue liquid...can't find one to buy however. Small town and don't want to Ebay in this cold Canadian weather ;)

 

Can regular old food coloring work in there or will it just make a mess of things. She doesn't want to attempt it unless someone here can assure her it's safe.

[LampHead]

Most likely you can but a picture would help to make sure. If its a cheap one like you said its probably water based and can be colored.