Click the Reference Plane tab to choose whether the reference surface is displayed in the ply stack plot and to control the appearance of the reference surface. Conventional shell elements use the reference surface to define the geometry of the part. Therefore, you can display the reference surface only on shell composites; you cannot display the reference surface on continuum shell composite layups or solid composite layups. In addition, if the ply's offset is defined by a distribution, Abaqus/CAE cannot display the reference surface.
To customize the appearance of the reference surface in a ply stack plot:
Locate the reference surface options.
Click the Ply Stack Plot Options button from the prompt area, or do one of the following:
In the Property module, choose View
Ply Stack Plot Options.
In the Visualization module, choose OptionsPly Stack Plot or click the 
tool in the toolbox.
Click the Reference Plane tab in the Ply Stack Plot Options dialog box that appears.
Do the following:
Toggle on Show reference surface to display the reference plane in the ply stack plot.
Choose the color and translucency of the reference surface.
Toggle on Show reference outline to display lines around the edge of the reference surface. Choose the color, style, and thickness of the lines.
Click Apply to implement your changes.
The ply stack plot changes to reflect your specifications.
By default, your changes are saved for the duration of the session and will affect all subsequent ply stack plots in that viewport. If you want to retain your changes for subsequent sessions, save them to a file. For more information, see “Saving customizations for use in subsequent sessions,” Section 55.1.1.