dark 最普通用词，指缺乏自然光线或人工照明，使某物漆黑无光或光线十分微弱。
dim 指光线不足或视力较差，不能清晰地看见物体。
black 侧重颜色是黑色的，有时也指无光的黑暗。
gloomy 指光线不足或部分光线受阻而出现的阴暗。
obscure 指因光线不充足而使物体灰暗不清，失去光泽或若隐若现。作借喻时指因复杂、深奥或含糊而难于理解。
vague 通常作借喻用，形容抽象事物。
grey 与dark意思相近，但侧重阴暗单调的意味。
参考例句
1. The population of China is set to grey. 中国的人口开始趋于老化。
2. The sea was red and the sky was grey. 这个海是红的（鸿海），而且天空是灰色的。
3. Colour: black, grey, blue, red, green etc. 色泽：黑色，灰色，蓝色，红色，绿色。
英英解释
n.
1. United States writer of western adventure novels (1875-1939)
2. Queen of England for nine days in 1553; she was quickly replaced by Mary Tudor and beheaded for trea
3. Englishman who as Prime Minister implemented social reforms including the abolition of slavery throu
4. any organization or party whose uniforms or badges are grey
5. a neutral achromatic color midway between white and black
6. clothing that is a grey color
7. horse of a light gray or whitish color v.
1. make grey
2. turn grey adj.
1. of an achromatic color of any lightness intermediate between the extremes of white and black
2. showing characteristics of age, especially having grey or white hair
3. used to signify the Confederate forces in the American Civil War (who wore grey uniforms)
4. intermediate in character or position
5. darkened with overcast
