The goal is to get 2 red shapes, but since the color changer is above the other red block the orange block would turn red and they would merge, resulting in a single red shape.
Because of this, you need to freeze the orange block before changing its color. The trick in this level is to know that a block doesn't change it's state (frozen/not frozen) when it's touching both a freezer and defreezer at the same time.
Play Level "Heat Cycle"