Bizer,
I printed out the picture in this post and looked at it under a red light. Everything looks great. Because the difference in printers, etc, you should still verify that the actual map that will be sold has visible red buoys under a red light.
Heck, maybe you could even get your retailers to sell handheld red lights next to with your charts! Or red headlamps? The possibilities are endless. "Bizer's charts save your night vision!"
Something like:
http://www.amazon.com/Celestron-9358...8374805&sr=8-2