The light generated by Led is not reacting the same way when going through a red and green colored nav light lense, because thIS light have a more discontinuous spectrum than an incandescent bulb light.
The led light absortion can go up to 80% in red filters , with a pink output and 60% in green with a blue output. You can understand immedialty it is impossible with such attenuation that a BAY15D 25w incandescent bulb giving 200 lumens can be securely replaced by a 2 watt white led bulb, even giving 140 lumens, as some led bulb manufacturers claimed. The absorbtion varies also depending what coloring chemical charge is use in the plastic lense.
Only in white lense mooring fixture a white led bulb can be use securely because there is no difference in light absorbtion .
Led bulb can be used in red and green fixture securely if the bulb manufacturer suplly a ligthing test ( preferarably realized by an independant european lab ) showing that for each manufacturer colored lenses ( Hella, Aquasignal, Ocullati, Trem, Lazilas , .. ) the color and intensity of light is in the International Martime organiation Colreg specifications ( EN 14744 is european translation ).
With a 5 W bulb to cope with these attenuation problem, the EMI emission are obviously higher . But limits given by EN norms are lower because the navigation fixture can be positionned on the mast top, only a few centimers away from the VHF and AIS antenna.