A method includes receiving a plurality of data points including electrophysiological (EP) values measured at respective positions in at least a portion of an organ of a patient. Some of the EP values are classified as outlier values in accordance with a defined criterion. A visual representation of at least the portion of the organ is derived from the plurality of data points. The visual representation represents the EP values with respective colors, and visualizes less than all the outlier values, by performing one or both of (a) identifying outlier values that deviate from respective neighboring EP values by less than a defined deviation, and representing the outlier values using colors that match the neighboring EP values, and (b) setting for the visual representation a mapping, which maps the EP values to the colors and which excludes at least some of the outlier values.