Final answer:
The run-on sentence from the provided list is 'This is not what I requested, the color is too dark, and it's the wrong size.' It can be corrected by dividing it into separate sentences or by using proper punctuation and conjunctions.
Step-by-step explanation:
The sentence that is either a fragment or a run-on sentence is:
This is not what I requested, the color is too dark, and it's the wrong size.
This particular sentence is a run-on because it consists of multiple independent clauses improperly joined without sufficient punctuation or coordinating conjunctions. To correct this run-on sentence, the clauses could be separated into individual sentences or joined with appropriate conjunctions and punctuation, such as semicolons or periods.