Using layers to control visibility and color
Layers in Visio are like different sheets of acetate, one on top of another, like we used to do with overhead projectors at school many years ago. We could add or remove these acetate sheets to show or hide their contents. However, Visio is more complex because all shapes in Visio can be optionally assigned to one or more layers, and all of the flowchart shapes have been pre-assigned to a layer called Flowchart. The Dynamic connector shape has been pre-assigned to a layer called Connector.