what is causing the shutters to fade like that &
how can I get the red off the bricks

The shutters were made from a poorly compounded PVC. Durable red colors are
difficult to make due to pigment instabilty in sunlight. Thats why your owners
manual urges you to keep your Ferrari covered when you spend a day at the
beach.
The red stain will probably require some aggresive treatment to remove, and
given this problem I'd first try a small rental blaster outfit with some mild
abrasive, plastic bits, walnut shells, or some such. Good luck.

Joe