In the sentence "If the scenery panels do not look good, the audience might not enjoy the play," the pronoun "it" can be corrected to "they" to maintain grammatical consistency.
So, the revised sentence would read: "If the scenery panels do not look good, the audience might not enjoy the play."
Here, "they" refers to "scenery panels" which is plural. Therefore, the correct pronoun to replace "it" is "they."