Color edge detection has been normally based on the vector extension of classical (scalar) derivative operators. This extension has been done either by the independent processing of each color component and aggregation of the partial results or by the synthesis of a special color space, featuring a single highly relevant component. These approaches fail to embed any visual perception information. This paper proposes the use of a perceptually relevant dissimilarity measure, based on a fuzzy color model and on a spatial symmetry color spread index as the basis of a color edge detector.