What you want is something called black light blue. The lamp itself appears completely black when off and when on glows a very deep purple and does not look bright at all. However things will glow VERY brightly in presence of this emission. If you have anything in your case vaguely fluorescent it will glow extremely bright as in "hurt your eyes to stare at it" bright! Those green DFI SATA cables and parts of their motherboards will glow extremely bright under this kind of light.