Flashlight for coral viewing

[evilskudd]

Is there a type of led flashlight that can be used to view the colors of corals in their full glory? Like a backlight flashlight or a royal blue led flashlight? What is the best thing to use for something light this?

 

[lnevo]

I saw these diy flashlights with a single led and aa batteries...not sure what wiring is required, but they were very cool.

 

[evilskudd]

What type of led though? Like royal blue? Or the small lights they use to detect counterfeit money?