Here is my blue NetNewsWire icon in my dock. ... In my dock, I have many items. I find the target by placement in the dock order, and then by color/ visual recognition of the item to be selected. While it is true that NetNewsWire's icon is mostly blue, I do not fing that a problem when compaired with most of the other icons in my dock. See Dock Icons

On the other hand, I would not mind a subtle RSS bar on the icon. as indicated in the Dock image that includes NetNewsWire. See Dock Icons