Magic mugs go through a specific manufacturing process.
First your logo is printed onto the mug. After the print has set then the magic mug coating is sprayed onto the mug. The magic mug coating is what allows the mug to change colour according to the temperature of the mug.
Something to be cautious of is that the magic coating alters the colour of the initial pront. This means that even if the mug is printed with your exact pantone colour, it will appear to be a different colour when the mug is sprayed with the coating.