White antennas work just as well as black ones. Silvery antennas work well too, because they’re exposing the aluminum bits that do all the work. Really, it doesn’t matter what color plastic is on your antenna. That may not make sense to you so let’s go through it
What does the plastic part of an antenna do?
Really, it’s mostly there for show. In some cases the plastic adds some rigidity to help the antenna stay together better. Sometimes it’s just a plastic covering to make the antenna look unique. In the case of our Televes antennas, the specific orange color acts as a brand identifier, distinguishing those antennas from copycats.
Does the color make a difference?
In general, no. That’s on purpose. The coverings of antennas are engineered with dyes that don’t have any effect on RF transmission. When antennas are developed, they are tested with and without the plastic coverings. Of course by the time an antenna gets to that point the manufacturers know what the answer is anyway. They’ve worked with chemists to make sure that there is nothing in the plastic that blocks radio-frequency radiation.
So, you could paint an antenna, then?
Sorry, that’s a big no. You could always get lucky and use a paint that didn’t cause problems, but that would take a lot of luck. Most paints still use metal pigments and those pigments can scatter signals before they get to the antenna. Here’s an example:
Yellowish colors come from chromium which doesn’t do a good job with signals.
Red comes from iron oxide or from natural materials that are high in iron. Iron does a good job with signals but paint doesn’t keep the particles in a good orientation.
Green comes from copper oxide. Copper is great for signals as you probably know but copper oxide isn’t. That’s why it’s really important to make sure your cables haven’t turned green.
Blue comes from cobalt or plants that are high in cobalt. It’s really bad at signal transfer as well.
So as you can see you’d have to be incredibly lucky to paint an antenna and have it still work.