@erpu maybe a variation of logo A with *two* stripes that quotes the € ? or a quote of the 12 star circle? are 12 stars enough to draw the shape of a train, C-style?
(of course € is not for the whole of europe, but the 12 stars are: not only for EU but for the whole of Europe, whatever that is)
@janamarie this is a variation of a "Gymnasium"(DE) physics experiment that shows light is quantised btw: when it's already shown that electric current is quantised and light of a specific colour "can't" be produced with current below some voltage, it follows that light is also quantised.
(and I'm putting "can't" in quotation marks here since incandescent lamps can do that)
@janamarie oh, and to spell out what I implied: run the LED with this extremely low current limit, let the voltage go 
@janamarie find a supply that supports very low current, low enough that even at 100% efficiency UV-C wouldn't hurt you.
at this low current the LED will be very close to it's photon energy / unit charge so voltage is colour after appropriate conversion (e·U = h·c/ where e=electron charge, U = LED voltage, h = planck constant, wavelength)
