What is the best color of contacts for dark eyes?

I have tried 4 colors of colored contacts: brilliant blue, pacific blue, sterling grey, and violet in the freshlook color brand. The iris of my eye looks dark and 3-D. When my friend with blue eyes tried on the same color contacts her iris looked normal.

My eyes are dark brown, other than colors in the brown family, does anyone know a color that doesn’t make the eyes look strange up close?

Thanks!!