The colour of and Akoya pearl is determined by the nacre. Environmental factors as well as the specific oyster also play a hand in the pearl's colour. After harvest, the pearl may undergo treatments to enhance or alter colour. While white pearls are still by far the most popular, darker pearls with a metallic - satiny sheen have recently commanded a demand in the fine jewellery market.
White Akoya Pearls
By far the most popular, white Akoya have been the standard pearls that belong in every woman's jewellery wardrobe.White Akoya pearls, as a colour category, encompass light creamy pearls as well as those with an overtone. The overtone of a pearl is the colour a pearl reflects that lies just above the pearl body colour it self.
In the white colour family, overtones range from pink to a creamy, ivory, or silver. Pearl colour and overtone can vary slightly under different lighting sources and ambient colours, as a result of the pearl's makeup. For example, fluorescent light, an overcast sky and shaded light tend to intensify blues.
Regular incandescent light bulbs as well as a rising or setting sun tend to intensify reds and yellows. For the truest colour, choose natural sunlight about midday. Most importantly, the pearls themselves will best reflect and radiate the ambient light from the wearer. Her skin tones, her colouring and clothing will subtly effect the colour of the pearls' shine.
Black Akoya Pearls
With the popularity of black Tahitian pearls, dyed Akoya with a metallic shine has gained prominence in the fine jewellery market. Dyed Akoya pearls are genuine and have been available in fine jewellery establishments since the 1930's. Today, demand for dyed Akoya pearls has greatly increased.
Treatment allows consumers access to colours that are not naturally available and at smaller sizes than traditional Tahitian pearl. Most dyed black pearls are under 8mm to 9mm where as black Tahitian pearls are not as readily available in that size. These pearls will exhibit more of a metallic shine than traditional white ones. Their darker colours are brought on by irradiation or a silver salt treatment. The treatment permanently changes the nacre of the pearls. The metallic iridescence resulting from these treatments is very beautiful. The most popular are black with green-peacock, deep sapphire blue and dark onyx black. Blue pearls have also become popular, ranging in shades of dark blue to light aquamarine. A well treated pearl will display even colouring and a metallic shine.