When selecting the manipulator handles in the OSG viewer in multipane mode the orthographic view panes will take on a colour overlay.
The attached video demonstrates the issue.
Steps to reproduce:
Open the example pony scene
Open the OSG viewer tab
Put the viewer in four pane mode
Put the viewer panes into different persp, front, top, side
Select either the x y or z of the transform manipulator in the persp view
Observe that the orthographic views will take on a color overlay