impartial 侧重对任何人或任何一方没有成见或偏袒。
just 多用于庄重场合，指不受个人利益得失或感情倾向的影响，侧重按照公认的准则或标准处理问题。
fair 普通常用词，指不偏不倚地对待人和物，侧重不受个人感情、偏见或利益所影响。
neutral 强调持中立态度，不偏袒任何一方，甚至不作最后的裁决。
objective 着重客观、真实，不为个人偏见、兴趣、感情或看法所左右。
参考例句
1. White is a neutral color. 白色是一种中性色。
2. The election officials were not neutral. 选举官员并不是中立的。
3. They are a by-product of the learning process, created by you, in themselves quite neutral. 它们是学习过程由你创造的一个副产品，它们本身是非常中性的。
英英解释
n.
1. one who does not side with any party in a war or dispute
2. neither moral nor immoral; neither good nor evil, right nor wrong
3. having no personal preference
4. having only a limited ability to react chemically; chemically inactive
5. not supporting or favoring either side in a war, dispute, or contest
6. having no net electric charge; not electrified
7. of something that is lacking hue
8. possessing no distinctive quality or characteristics
9. lacking distinguishing quality or characteristics
