Item & group title colors
Item's title background color may be used for grouping items in diagram and may vary in wide range of colors. at the same time title font color should be always readable on every background. So taking these considerations into account widget allows to customize title background color for every Item with itemTitleColor property and provides means to choose the best title font color out of two options: itemTitleFirstFontColor and itemTitleSecondFontColor. Widget uses primitives.common.highestContrast function to choose font color having highest contrast on item's title background. See reference.