Spline handles are used to manipulate the shape of a spline at the spline points. There are two colors for the spline handles: blue and gray. Blue spline handles are handles that have been edited, whereas the gray spline handles are the ones that were originally inserted.
The blue spline handles can be made visible even when the spline isn't selected.
This option can be toggled by right clicking on the spline->"Show Spline Handles".
If the spline handles are completely missing when clicking on the spline, they can be enabled by going to Tools->Options->System Options tab->Sketch "Enable spline tangency and curvature handles".
If the above steps do not resolve the issue covered in this article or if you have any questions, feel free to contact Hawk Ridge Systems Technical Support at firstname.lastname@example.org.