Jose wrote:
I've noticed myself that the green (in airport beacons) is often not a
well saturated green, and the green (on wingtips) is often blue.
Perhaps secondary colors would work better for colorblind people while
not being hard to distinguish for normally sighted people.

When flying at night (at a distance) I often have to watch the beacon
for a bit to discern white from green. After a few cycles I can tell
the brighter white from the dimmer green. On a sunny day the red &
white lights on a VASI often are hard to tell apart until I'm within 1
mile. I have a red/green deficiency but can tell white from green from
red well enough to have passed the signal lamp test to get a SODA.