change background color for the statement part in a side by side question using javascript

Hello, I am trying to change the background color of the statement column only in the side-by-side question. (Change the color for the "Please rate the song" column only).

I have been trying using JS for this:
jQuery("#"+this.questionId+"QuestionStatementBody").css("background","#323531");

But it seems that there is no "QuestionStatementBody" option, can anyone help provide a solution?
Thank you so much for your help in advance!