On Mon, 13 May 2013 13:53:44 +0000 (UTC), Danny D
wrote:

On Mon, 13 May 2013 06:37:41 -0700, wrote:

It seems to me a curious thing that they paint them black.

You have an interesting point there, in that it's the 'paint' and
not the 'color' of that paint that protects PVC from UV radiation.

Dunno why mine are black ... but ... since they are ... I'm going
to get out my license to prove I'm over 18 and have them unlock
the double padlocked spray paint cage at Home Depot when it's all
working and buttoned up ... and grab me some flat black stuff to go!

http://www.krylon.com/products/fusion_for_plastic/