For the exhaust shields, google for 'Tiger 131 exhaust shields' - that will give you a good idea of where the normal paint colour stops and where it starts to discolour and darken. Remember that the shield has a chimney effect, so while it may be close to a hot casting at the bottom, there is cold air being drawn in that will cool the lower parts before becoming progessivly hotter and less able to counter the infra red radiation from the encased exhaust stack as it rises.
Also make sure you seal the salt properly, otherwise moisture will get in and start to flake the paint off - I have the same trouble with my exhausts when I use baking soda - looks amazing when first done, but not so much after a year or 2
