I didnt watch either as a kid so I have no idea what you are talking about.
Shortly after transformers became popular, some fake ones started coming out. This caused the company to start putting stickers on the original transformers. The stickers were black, but if you put your finger over the sticker, it would cause it to show the transformer emblem. As you got the emblem hotter, it would change colors. Start out as blue for just a small amount of heat, then change to red for the hottest.