I wrote an article [1] a few months ago about whether wind turbines are ugly and how/if they could be made more beautiful. Painting them black is definitely not going to be received well by people that consider them ugly.

The most interesting solution I came across was using LED lights [2] to match ambient colors of the sky. Here’s the description from the prototype creator:

I built a scale prototype using a foam core silhouette of a wind turbine as seen from land. The structure was covered in LED Tape lights and linked to a potentiometer to control their brightness. I installed the turbine along the San Francisco beach and powered it using a car battery. After some quick adjustments, the silhouette vanished into the background sky.

I think this solution, combined with some kind of flashing ultraviolet signal (as birds can see UV, IIRC) is the best route for both birds and humans.

1. https://onthearts.com/p/are-wind-turbines-ugly-could-they

2. http://www.taismauk.com/#/camouflage-for-offshore-wind-turbi...