In this study we report on issues related to the use of color as a third dimension on graphical representations provided to students. We find that a majority of the students sampled have a preconceived color map regarding temperature, with blue indicating low temperatures and red indicating high temperatures. Attempts to transfer this particular color map to representations of other quantities, however, may not be successful. In particular, when displaying a topographic map we found that students had a predilection to visualize a hill, regardless of the color map used. Moreover, many students ignored a systematic use of color in favor of seeing a hill in the representation. This suggests that a representation of a feature that seems obvious to an instructor may be interpreted to have a different meaning by a student. Hence, care should be taken to ensure that students interpret the use of color in figures the way the figures are intended.