A color coding system is used to quickly identify items in photos that are referenced and those that are not referenced. This applies to point, curve, edge, Bent Tube, cylinder, and silhouette marks. Marks on photos that have not been referenced are displayed in gray. Once the item has been referenced on at least two photos its color changes to white on photos.
During referencing mode additional colors are used to illustrate a point’s referenced state. Objects selected for referencing on the source photo are displayed in the red selection color. When over a destination photo points already referenced on the source photo are yellow. The active point on the source photo has its ID displayed yellow if it has not yet been referenced on the destination, if the active source point has already been referenced on the source it will be purple.
Representative colors can be selected on the Colors page of Preferences - User Interface.