Is it possible to set the edge color to WHITE for entire actor,then set the edge color of specific cell to RED?
No, it is not. At least the way you want. Depending on the underlying data type, it is possible, via a simple assignment of scalar values, to have some of the edges in a different color:
However, to achive the exact effect you want, your data object needs to have cells of type
VTK_LINE. The figure below illustrates the cell types you can define (not only squares, triangles or cubes).
Then assign colors accordignly to the edge cells surrounding the higher order cell you want to highlight.