Is Pluto a white dwarf planet?

Answer 1

"White dwarf" typically refers to a small hot star off the main sequence--after its collapse from a red giant. This is in contrast to a red dwarf which never got big enough to expand to a red giant.

Pluto, in contrast, is a dwarf planet--far smaller than any star. It is essentially a big dirty snowball. So its albedo is high enough (it reflects enough light) to make it appear light gray in color.