I'm not sure I understand your question. Salmon (as in salmon faverolle) is silver plus mahogany. I don't see a dirty red brown cast to them.
I am not quite sure how you are distinguishing blue penciled from blue partridge? They are the same? And blue partridge has gold (or red) ground, not silver.
I am not quite sure how you are distinguishing blue penciled from blue partridge? They are the same? And blue partridge has gold (or red) ground, not silver.