Don't buy the duplicolor "Caliper" kit, just use the duplicolor engine enamel. The Brembo Calipers off my Treg have been superheated, power washed, seen gravel roads, and plenty of corrosive brake dust and sand. They were painted almost two years ago and still look like new.
Make sure and clean the calipers really well to remove all brake dust and corrosion. Apply multiple thin layers, waiting about 20mins between coats. Allow to dry after last coat for an hour then apply a couple coats of clear 20 mins apart.
Then allow paint to cure for at least 24 hours before heat cycling, preferably 7 days cure time if you can stand not riding that long. lol
You will not be disappointed, there is no way your bike will see the abuse my brembo's have seen.
Remember, preparation is paramount with any successful paint project.