Human eye works well with yellow (natural light). LED lights emit different frequencies. Although the candle power or whatever it is called is equal or more than normal hot filament light, it is not visible to the human eye. The objective of anchor light is "to be seen". Make sure you use hot filament light or similiar that is visible to human eye.
Our LED anchor and nav lights are very visible and meet all coast guard requirements. Where are you getting your info from?