The filter allows light 590 nm and above, not just red. If you look at the spectrum of direct emission XP-E green, there is some light above 590 nm, so at least it can penetrate. The cyan being unable to penetrate means it is shifted even more towards shorter wavelengths, as one would expect from direct emission. Phosphor converted will have a wider spectrum and there will be light above 590 nm, like in lake blue or azure LEDs. With lake blue, you can see from red to blue. Azure also emits light above 590 nm.