Cats, you said "In Africa and in the Caribbean the people there have the same type of tradition when they cover their faces in white clay or mud so they cannot be recognised."

While the use of white ashes or white paint might have been used to disguise a person, it might be well to ask the purpose of that disguise...

As a student of African cultures, I would submit to you that traditionally those people who wore masks did so to symbolize and become like [or become/be possessed by] ancestors, forces of nature, or divine beings.

If you are truly interested in this subject, you might want to visit any number of websites on mask traditions in Africa and elsehere.

One such site is http://cti.itc.virginia.edu/~bcr/African_Mask.html

See this quote from that site:

"African masks are dramatic portraits of spirit beings, departed ancestors, and invisible powers of social control. Each mask was made according to a traditional style, and each was worn by a trained performer. The African masks that hang on walls of Western art museums, detached from their full-body costumes, were originally part of whole performance ensembles, consisting of elaborately costumed dancers, vibrant music, and highly stylized dances. These complex ceremonial events expressed important social, religious, and moral values for the whole community. With careful attention to the masks' artistic and symbolic detail, it is possible to perceive these same values within the masks themselves..

Also, you might also want to read up on color symbolism in African cultures and other places in the world.

See this quote:

In the scheme of things, black, red and white tend to rule the arts and crafts of sub-Saharan Africa. They are followed by blue, yellow and orange. These are colors of mineral, animal and vegetable origin and thus easily accessible. Black can be seen everywhere since it is the skin color of most African peoples. Garnered from roots, seeds, charcoal and soot, it is also the color of the fertile earth and thus speaks of completeness and plenty. To achieve the rich black color of a cloth, the fabric is often dyed in fermented mud. Yet black is also associated with death, illness and uncertainty and has remained a powerful part of African shamanism.

    The color red, obtained from seeds, berries, stones and minerals, implies energy, vitality and joy, and the colors yellow, orange, violet and green are often considered a shade of red. White, traditionally meaning purity, also conjures up images of supernatural forces, danger and death and is carefully gleaned from limestone, plant ash and animal waste.

   In the adinka [kinte] cloth of the Ashanti in Ghana the white weave signifies purity and virtue; black indicates deep feelings of melancholy, the devil, death and old age; green means vitality and newness, gray blame and shame. Gold is the color of royalty and shades of yellow are likened to the fat of a luscious foul and the juice of a ripe pineapple All three suggest comfort and warmth.

   But the most meaningful and widely used color south of the Sahara is ochre. For more on African Color Symbolism

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It may be possible that contemporary Africans use white paint to cover their faces as another form of disguise..borrowing perhaps from European traditions...

For instance, there is a widespread African American church mime tradition that I would perhaps date from the 1980s. White paint is used to cover the faces of these [usually youth female or male, but sometimes adult female troups. The performers also wear white gloves to cover their hands..IMO, this tradition is directly connected with European mime traditions. White paint is used to emphasize facial features and the color white here also symbolizes purity..

I'm far from a fan of this custom of white painted Black mime groups. However, for the record I wanted to mention this performance practice.

Hopefully, this is not seen as too far a thread drift from the subject being discussed...

Azizi