My adult shrimp range in color from a medium blue to a pale icy blue. The shrimp shown below are typical of the adults. You will be shipped younger shrimp which will not have full color yet. I will not be trying to grade the shrimp, it's scoop & ship.
The color of an individual shrimp does vary by mood, surroundings and temperature. They seem to look best on a dark substrate, lots of plants, steady water parameters with somewhat cool conditions. They may not look blue when you receive them. Full color will not be reached until they are mature adults. Occasionally a shrimp will be very bright blue as a youngster but that is the exception.