The original white lead pigments have oxidized and turned black.

原来白色的铅颜料已经氧化发黑了。

《柯林斯英汉双解大词典》

The lead pigments are a big source of lead pollution.

含铅颜料是主要的铅污染源。

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Yet the alchemists had their triumphs, inventing brilliant new pigments, perfecting the old - red lead oxide, yellow arsenic sulfide, a little copper and vinegar and you've got bright green verdigris.

尽管如此，炼金术士还是获得了许多成就，他们创造了色彩鲜艳的天然色素，使原来的色素更完美——红色的氧化铅，黄色的硫化砷，少许铜加上醋，你就会得到明亮的绿色的铜绿。

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Some of the older pigments are lead-based and difficult to acquire because of EU health-and-safety regulations.

WSJ: Forging Ahead With a Goya Classic

Glaze is mostly translucent, but da Vinci would also slip in small amounts of pigments, such as manganese and lead oxides.

ECONOMIST: The da Vinci method

The albino condition, caused by a lack of colouring pigments in the skin, can lead to the animal being susceptible to sunburn, but the zoo said its wallaby enclosure had lots of shade and it should lead a "normal life".

BBC: Rare albino wallaby born at Linton Zoo