“变阴暗”常见的英文表达可以是 become gloomy 或 turn dark/gloomy，具体使用哪个表达取决于语境：
become gloomy：更侧重于描述氛围、情绪或天气等变得阴沉、不愉快。例如：
The sky became gloomy as the storm approached.（随着暴风雨的临近，天空变得阴沉起来。）
His mood became gloomy after hearing the bad news.（听到这个坏消息后，他的情绪变得阴沉起来。）
turn dark/gloomy：既可以描述物理环境（如天空、房间）变暗，也可以描述人的情绪或心境变差。例如：
The room turned dark as the sun went down.（太阳下山后，房间变暗了。）
Her face turned gloomy when she realized she had lost her wallet.（当她意识到钱包丢了时，脸色变得阴沉起来。）