blue-black

例句：

1. 1.The sky was a deep blue as the sun set.
   当太阳落山时，天空是深蓝色的。
2. 2. The shoes are a deep blue color.
   那双鞋是深蓝色。
3. 3.The dress is a deep blue, and it looks very elegant.
   这件衣服是深蓝色，看起来很优雅。