Wilton has silicon brownie trays that will do the trick. You have to boil the isomalt with 10 percent water, brush down the sides with water, do not stir. using a thermometer, the sugar has to come to a certain temperature, then you swirl in your food color which will bring the temperature back down slightly. Once it comes back up to temperature, quickly take it off the heat and shock the bottom of the pan in cold water to stop the cooking. You can then pour into the molds.
It's late and I unfortunately don't have the exact temperature so you'll have to research this a little...I want to say it's 315F but please don't quote me, double check on that.
Disclaimer: severe burns can occur with hot sugar