In previous work [1] we compared three time series visualization techniques (colorfields, horizon graphs, and line charts) in small multiples [2], in order to determine if the time series results returned from automatic similarity measures are perceived in a similar manner, irrespective of the visualization technique. Our results indicated that the notion of similarity is visualization dependent. In that first study, our colorfields implementation used a naive RGB color interpolation between red and blue hues. In this research report we describe a follow-up experiment, comparing this simple RGB interpolation to one that is perceptually uniform (CIE L*a*b*), in order to understand if the choice of color interpolation plays a role in the perception of similarity.