The colors they chose make it darker and show the feeling of madness. the words on it could show how she is thinking a lot. By making her sick all mostly one color it makes her look sickly and on the verge of death. It brings an idea of death and sadness to the piece.
Explanation: This technique was used more commonly in the baroque era, employing the concept of terraced dynamics. The difference is often one instrument per part versus a full section. Your welcome :)