Sorry, you asked what color not what pattern. Think of peas as either winter hardy or tropical. The tropical are the Greens, they are very stately and come in only one variation although there are three different sub-species. Then the winter-hardy are the Indian Blue. All of the color variations are IB. Then there is a mix of the two that is called Spaulding which is just a mixing of the two types and the higher the Green blood the less winter hardy they become.
I have lost track of how many color variations there are, but it is around 20. There is also seven different patterns and when you add up all the different combinations that are possible you will come up with about 450 different possibilities.
So if someones tells you that your hen is Black Shoulder it is also a given it is IB unless a color is mentioned first. When we state what a bird is visually we start with the color, then the pattern, then any known splits. Splits are not always noticeable visually.
Your hen is India Blue color, Black Shoulder pattern, and it is noticeably carrying one of the white genes so it is split possibly to either White, Pied, Silver Pied, or White-eye.
