I have code similar to the following to allow the end user to set the palette they would like to use. You'll notice if the Longhorn scheme is selected I instead turn it into a custom scheme and just change the Window value in it. I change this value because the Longhorn.Window value makes it hard to see a mouse pointer and keyboard cursor over entry field controls.

private void miPalette_Click(object sender, CommandEventArgs e)
{
if (NUIManager.Palette.ShowEditor() == DialogResult.OK)
{
if (NUIManager.Palette.Scheme == ColorScheme.Longhorn)
{
NUIManager.Palette.Scheme = ColorScheme.Custom;
NUIManager.Palette.Window = Color.FromArgb(60, 58, 53);
}
}
}

Is there a way I can directly change the Longhorn scheme color values instead? Is this the best way to address this issue? Given I'm exposing the palette editor to the end user I'd like a little control over the contents of it.