This makes the colors in INSL cycle in heat mode. Because the temperature of INSL has no affect on the simulation (INSL is an insulator doesn't transfer any heat), it can be used in anything that requires insulator to be used, or even just for a decoration. To view the effect, switch to heat mode. (press 6 on the keyboard).

function test_update(i, x, y, s, n)
tpt.parts[i].temp=(tpt.get_property("temp",i)+500) % 9999
end
tpt.element_func(test_update, tpt.el.insl.id)