What is the gram reaction of Human papellomavirus?

The Gram reaction is used to classify bacteria into two broad categories, Gram positive and Gram negative. The Gram stain characteristics of a bacterium depends on its cell wall components and thickness. The viruses do not have any cell walls or other equivalent. The viruses are too small to be seen by light microscopy, only exception is the Pox virus. So the Gram stain is not appropriate for virus identification. However, if one is able to see papilloma virus through light microscope, these may appear Gram negative. Because the crystal violet dye would be removed by decolorizer, and the counterstain (safranin or carbol fuchsin) would show its color.