Red coloration is associated with aggression in many animals.

对很多动物来说，红色象征着进攻。

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Cut in a convex form known as a cabochon , this red tourmaline could also be called a rubellite because of its red coloration.

切割成一个弯如球形的样子就像是天然宝石的形状，这红色电气石也可以叫红电气石因为它有红的染色。

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The dorsal fin coloration of the male is a circular red spot ringed with blue which scientists said reminded them of Obama's campaign logo.

这条雄性的鱼，背鳍是蓝色，上面带着红色圆形点，科学家们表示会联想到奥巴马的竞选标志。

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Dr Robin Catchpole, senior astronomer at the Royal Observatory Greenwich, said the red coloration was a brilliant effect.

BBC: You are in: Sci/Tech

Dr Schaberg has found that the timing and extent of red coloration in different trees is consistently related to the concentration of nutritionally valuable nitrogenous compounds and sugars in the leaves.

ECONOMIST: The science of autumn