Hi All:
The best way to spot a two tone Dominion in my experiance, is to put the insulator on a piece of white paper. Pick a spot ( say 9:00 o'clock ) and rotate the insulator while looking downwards at the 9:00 o'clock position. If the color changes as you rotate the insulator, then you have a two tone piece. This is best done in good light, but not sunlight.
Yellow and orange amber two tones are easier to spot as the color separation is usually greater. Some times you can see amber swirling in the skirt by looking through the skirt from the inside against a white background.
A verticle color separation is much rarer than a horizontal separation, for those who get into detail
Looking sidways at an insulator is not the best way to spot a two tone, as the glass thickness can mess with one's color preception etc.
There are a couple of two tone shades in the lt green / straw / peach color combinations.
Think I have a spare if anyone is interested.
Good collecting in 2011
.......... Robin