Legend Item Text is not visible in Windows11Dark. This is because the LegendItem A possible workaround is to subscribe to the VisualItemCreating event. In the event handler, we can create a new LegendItemElement and set its ForeColor.
private void LegendElement_VisualItemCreating(object sender, LegendItemElementCreatingEventArgs e)
{
e.ItemElement = new LegendItemElement(e.LegendItem) { ForeColor = Color.Black };
}