Almost all Tortoise pickguards including popular branded items are made by printing a tortoiseshell look onto the back of the top layer. In the case of our tortoise pickguards the top layer is a clear celuloid material. The only exceptions are those where the tortoise layer is poured as a solid material and typically costing $300+ and very beautiful they are too but hand made and expensive.
We have red and brown tortoise pickguards and each one is different, you can get an idea of the variation in pattern by looking at all the listings of new and Vintage Relic S & T type pickguards.
There is an element of "pot luck" as we can't go through our stock picking out and photographing them and talking of photography of tortoise pickguards, we do not use manufacturers stock photos for any of our products, all are photographed here and tortoise is particularly difficult to colour balance. You can see the difference between a red and brown and the photos may appear darker or lighter than the physical item but it all depends on the light you are looking under.
So I hope this helps, we do get a lot of questions about tortoise pickguards and I hope this answeres some of them.