For Softimage. Set the 'Vertex Color' display option to 'Never Show' for all cameras and 3d viewports (lights excluded). This can be very useful when working with normal maps, due to the crazy performance hit from Tangent properties.

softimage_DisableViewportVertColor.py

from win32com.client import constants

for camera in [cam for cam in Application.ActiveSceneRoot.FindChildren2("", constants.siCameraPrimType)]:
    Application.SetValue("%s.camdisp.vcdisplay" %camera, 0)

for viewport in Application.Desktop.ActiveLayout.Views.Find("View Manager").Views:
    Application.SetValue("Views.View%s.UserCamera.camdisp.vcdisplay" %viewport, 0)	
    Application.SetValue("Views.View%s.TopCamera.camdisp.vcdisplay" %viewport, 0)
    Application.SetValue("Views.View%s.FrontCamera.camdisp.vcdisplay" %viewport, 0)
    Application.SetValue("Views.View%s.RightCamera.camdisp.vcdisplay" %viewport, 0)