White is a most dirty colour. Ask anyone who wears white pants or white shoes. How easy these pants and shoes can be dirtied. It is not a surprise that so many people in white managed administration were caught dipping their dirty hands into the honey jars or dirtying their white under wears in some quiet car parks and bonding trips.
That's an understandable, but myopic view.
White allows rapid detection of misdeed and dirt. The PAP is acknowledging that no one is perfect, there are bound to be black sheep who give in to a moment of temptation. White allows us to flush out these black sheep by making their dirt mark as visible to the naked eye as possible.
in this way, the PAP maintains its stature as uncorrupt and incorruptible.