Bleached P.v.c.

[soxmis_sid]

Is there a method for restoring the colour to brown PVC facia boards which have lost their colour due to sunlight?

[The Builder]

I prefer to paint them, sid, but you may not want to do that.

Maybe a trip to Halfords. Look for products that restore car body paint.
"T-Cut" or possibly a cutting compound.

[heathfield]

Or just try Cif to do the same thing as T-cut. In either case you'll be removing a very thin layer of bleached plastic and leaving behind a fresh polished surface.