I was looking for options like QGraphicsTextItem::setPen(), or even QFont::setColor() or QFont::setForegroundColor(). None of them exi
QGraphicsTextItem has a palette method which returns a QPalette and QPalette has the setColor method which takes a role.
void QPalette::setColor ( ColorRole role, const QColor & color )
The role you want is
QPalette::Text The foreground color used with Base.
This is usually the same as the WindowText, in which case it must provide
good contrast with Window and Base.