Use 0.1M standard NaOH solution titrant to titrate the solution from red colour to orange.

用0.1M标准NaOH溶液滴定剂，滴定到溶液由红色变为橙色。

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Lycopene is an antioxidant contained in the skin of tomatoes which gives them their red colour.

番茄红素是一种抗氧化剂，存在于番茄的外皮，使番茄呈现红色。

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Daniels says Western Australia's metamorphic rocks contain more iron than the igneous rocks on the east coast, making some of the beaches a more orangey-red colour.

丹尼尔说澳大利亚西海岸的变质岩比东海岸的岩浆岩含铁成分高，因此沙滩呈现橙红色。

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The dark red colour pervades everything, he says: the streets, the sides of the damaged houses and the forbidden zone beyond.

BBC: 'One year' to clean toxic spill in Hungary

This should produce a red colour if the metal contains any nickel.

BBC: Earring

Gap has banned extensive use of the colour red in its in-store ads to avoid causing offence.

ECONOMIST: American retailers