What is the color and shape of white blood cells?
The color is white, and the shape is always changing.
Hence the name, white blood cells are white. They do not have an exact shape however. Red blood cells have a set bioconcave shape, but the function of white blood cells does not allow them to have a set shape.
Due to the constant fighting of illnesses, white blood cells are always consuming bacteria in a process called phagocytosis. During this process, they move around the bacteria and engulf it, like the diagram below.
It would be very hard to do this process if there was one set shape, therefore, it's shape is never changing.