Blue aerosol paint explodes in kettle

(machine translated in 2018) Alain, a friend of mine wanted something surf spray with blue paint. Paint flows better and hard better if he what is warmer.
So Alain thought a good idea to have something to warm up a spray can: a kettle! (Don't try this at home!)

Little water in the kettle, spray can in there and then the kettle. After a moment, he hears a loud bang:
Photo of the result of a blue spray can that had exploded