[olga]

Winter Whites or hybrid dwarf hamsters with some WW genes in them will usually only change colour if the temperature drops sufficiently. Many of us living in centrally heated homes may therefore never see this change as Silver has pointed out.

The name Winter White probably refers more to the animal in its wild state.

Also some captive WWs may feel a change in temperature and get patchy marks on their fur rather than changing to all white depending on how sensitive they are to temperature change.