An apparatus and method are provided for visually displaying the present room temperature of a space, through the use of a thermostatic controller adapted for receiving a temperature input indicative of a temperature in a space, and having a housing that includes an illuminated portion thereof emitting a light having a characteristic of the light that changes as a function of the temperature in the space. In various forms of the invention characteristics of the light, such as the color or the intensity of the light, are changed as a function of the temperature in the space, to provide a visual indication indicative of the present room temperature of the space. The characteristic of the light may be changed as a function of the present room temperature, or as the difference between the present room temperature and a desired room temperature, or for other purposes.