Since Version ??? its possible for some Diagram-types to define the Fill-Color per optional →context→edit→context→DataRanges→DataSeries→Fillcolor <cellrange with "colorValues"> IHMO the Colors defined in that way should also reflect into corresponding colors in Legend-symbols - but unfortunatly doesn't... See attached Calc-doc with simple pie-Chart
*** This bug has been marked as a duplicate of bug 89257 ***