There is a bug in the Microsoft Gantt chart visual. When slicers are used on it and bar colors are assigned to specific Legend values the color of the Legend marker and the color of the bars do not always stay in sync. When the slicer selections results in only one value of the Legend field the Legend marker defaults to the first color of the legend colors but the bars stay with the color that was assigned to them in the format. See the pictures below. The first one shows where the colors are in sync. The second one shows where they are not.
