This is the 6544th most frequent Russian word.
darker
The Russian word "darker" is not a Russian word; it appears to be an English word.
Here, darker is used to describe the increasing darkness of the sky, indicating a change in the intensity of light due to the approaching storm.
Небо стало темнее перед грозой.
The sky became darker before the storm.
In this sentence, darker is utilized to compare the shade or tone of the paint, showing a relative difference between the two colors.
Эта краска темнее той.
This paint is darker than that one.
Here, darker is metaphorically applied to describe the tone of voice, implying it became heavier or more somber to match the topic of conversation.