Final answer:
The correct APA style for line spacing is to double-space throughout the paper, including the works-cited page, along with other specific APA formatting guidelines.
Step-by-step explanation:
The colleague has correctly followed the APA style for line spacing if they have double-spaced throughout the paper, including the works-cited page.
APA formatting guidelines specify that the entire document should be double-spaced, with one-inch margins on all sides, and paragraphs indented half an inch.
In addition to these requirements, page numbers should start on the first page and be placed in the upper-right corner, and identifying information and titles should be properly formatted and placed as per APA guidelines.
Lastly, any long quotations must be properly cited and formatted according to the APA style.