Whether it is arguing until 'blue in the face' or feeling 'green with envy' the English language is well-stocked with idioms linking color to emotion.
无论是争辩到“脸色发蓝”还是感觉“嫉妒得发绿”，英语中还真不缺将颜色和情绪联系在一起的习语。
Now for the first time, scientists have shown that people actually do change hue depending on their feelings.
不过这是科学家第一次表明，人类的脸色确实会随着情绪的变化而改变。
Although it is a subtle alteration to skin tone and complexion around the nose, eyebrows, cheeks or chin, the effects are picked up subconsciously by observers, making it very hard to hide emotions.
尽管只是鼻子、眉毛周围、双颊和下巴的肤色稍微有些变化，但是对方却能下意识地察觉到，因此要隐藏情绪真的很难。
It means that a sad person, attempting to put on a brave face will still flush the color of his or her unhappiness, inadvertently showing the turmoil behind their smile.
这意味着，当一个悲伤的人试着装出一副高兴的模样时，仍然会把自己的忧郁通过脸色表现出来，在无意间流露出了笑容背后的心酸。
The scientists believe the changes of color are triggered by blood flow channelled from the central nervous system depending on our state of mind.
科学家认为，脸色的改变是受情绪状态影响，由来自中枢神经系统的血流引发的。
"We identified patterns of facial coloring that are unique to every emotion we studied," said Dr Aleix Martinez, cognitive scientist and professor of electrical and computer engineering at Ohio State University.
俄亥俄州立大学电子与计算机工程学教授、认知科学家亚历克斯·马丁内斯博士说：“我们识别出了专属于我们所研究的每一种情绪的脸色模式。”
"We believe these color patterns are due to subtle changes in blood flow or blood composition triggered by the central nervous system. Not only do we perceive these changes in facial color, but we use them to correctly identify how other people are feeling, whether we do it consciously or not."
“我们认为这些脸色模式源于中枢神经系统引发的血流或血液成分的细微变化。我们不但察觉到了脸色的这些变化，还用它们准确识别出了其他人的情绪，无论是有意还是无意的。”
For the study, the researchers first took hundreds of pictures of facial expressions and separated the images into different color channels that correspond to how human eyes see color - either in a red/green channel or blue/yellow.
为了开展研究，研究人员首先拍摄了数百张脸部表情的照片，并将这些照片按照人眼感知颜色的方式相应归入不同颜色通道——红/绿通道或蓝/黄通道。

They then ran the images through computer analysis and found that emotions such as 'happy', 'sad', 'anger' or 'disgust' all formed unique color patterns.
接着他们用电脑对照片进行分析，并发现“快乐”、“悲伤”、“生气”或“厌恶”等情绪都能构成独特的脸色模式。
'Disgust', for instance, creates a blue-yellow cast around the lips, but with a red-green cast around the nose and forehead.
举例来说，“厌恶”会让嘴唇四周泛出黄蓝色调，而鼻子和前额周围则会呈现红绿色调。
Happiness is seen in red at the checks and temples and a little blue around the chin, but the same face with a slightly redder forehead and slightly less blue chin registers as 'surprised.'
快乐的人脸颊和太阳穴发红，下巴周围则会有点发蓝，但如果前额略微更红些，下巴没那么蓝，那么这个人的情绪则是“惊讶”。
Although the team did not look at 'envy' they suggest that the green color linked to feelings of jealousy could stem from the nausea which often accompanies the emotion.
尽管该研究团队没有关注“嫉妒”，但他们指出，和嫉妒有关的绿色可能源于经常伴随嫉妒的憎恶。
To test whether colors alone could convey emotions - without smiles or frowns to go along with them - the researchers then superimposed the different emotional color patterns on pictures of faces with neutral expressions.
为了测试在没有伴随笑容或皱眉等表情的情况下脸色本身能否传达情绪，研究人员将和情绪相关的不同脸色模式加在面无表情的人脸照片上。
They found that volunteers were able to spot an emotion up to 75 percent of the time. The effect remained regardless of gender, ethnicity or overall skin tone.
他们发现，志愿者识别出情绪的准确率达75%。无论男女、种族或肤色，效果都一样。
Next, researchers showed participants facial expressions of happiness, sadness and other emotions but mixed up the colors of the images, for example putting an angry hue on a happy face. Participants reported that something was 'off' but could not put their finger on what was wrong.
接下来，研究人员让参与者看快乐、悲伤和其他各种面部表情的照片，但却把脸色模式混搭了一下，比如将生气的脸色放在快乐的脸上。参与者报告称有点“不对劲”，但说不出是哪里出了问题。
"Participants could clearly identify which images had the congruent versus the incongruent colors," added Prof Martinez.
马丁内斯教授补充道：“参与者可以清楚地识别出哪些照片的脸色很和谐，哪些照片脸色不和谐。”
"People have always said that we use makeup to look beautiful or younger, but I think that it is possible that we actually do it to appear happier or create a positive perception of emotion--or a negative perception, if you wanted to do that."
“人们总是说我们用化妆品来使自己看起来更美丽或更年轻，但我认为我们实际上也可以通过化妆来让自己看起来更快乐或营造出积极的面貌，或是消极的面貌，如果你愿意的话。”
It also enabled researchers to construct computer algorithms that correctly recognize human emotion via face color up to 90 percent of the time.
依据这一原理，科学家还构建出能够通过脸色准确识别人类情绪的计算机算法，准确率达90%。
Happiness was the easiest emotion for the computer to recognize by color alone, and it detected the emotion with 90 percent accuracy. Anger was detectable by color alone 80 percent of the time, and sadness 75 percent of the time. Fear was recognizable 70 percent of the time.
快乐是单看脸色的情况下最容易能被计算机识别出的情绪，准确率高达90%。单看脸色识别生气的准确率为80%，悲伤则是75%。单看脸色识别恐惧的准确率为70%。