Green screen effects like you see when someone is presenting a weather forecast are produced by having a computer watch a green background. The computer then paints the weather backdrop on everything green.
Since the presenter isn't green, they look like they are in front of the background. In the studio, there's just a green sheet behind them.
While it would be cool to do the same thing with a panoramic head, you'd need another camera underneath the tripod head(obviously you don't have a picture of the area under the tripod already, or you wouldn't be shooting the panorama to begin with), to feed an image to a computer, etc.
Actually the more I think about it, the way the light hits the tripod would make different luminosity values of what ever color it was. That probably would make it harder to select that particular color as a selection to turn into a mask. I don't know. It would be worth experimenting with.
But even better than a colored tripod would be a simple cone that fits over the tripod so that you would only have to select around a circle instead of all the different angles and fittings and separate legs of the tripod.
I believe the largest factor is consumer demand - just hasn't been a lot of requests. When Nick produces many of these parts the anodizing is done in batches to cut costs. Doing different colors would be expensive especially if they didn't sell.
But I agree, even at a higher cost, it would be great if Fanotec could accommodate with any custom color a customer chooses.
That said how much more you would be willing to pay for an all blue head?