How to clear background color on table row

I have version 7.4.3.2, Windows 10. I can set a background color on a row, but I can’t remove the background color. I’ve tried every suggestion I can find. I’ve tried Table > properties > Row > none, Table > properties > Row > color > white. In fact I can’t change colors on the row at all. Is it possible the row background was set by some other, apparently immutable, way?