A user can set color-table entries in a PHIGS application program with the function
(a) setColourRepresentation (ws, ci, colorptr)
(b) setColorRepresentation (ws, ci, colorptr)
(c) setColour (ws, ci, colorptr)
(d) setColourRepresentation ()
I had been asked this question in an interview for job.
Enquiry is from Color and Grayscale Levels in portion Graphics Primitives of Computer Graphics