What color typically signifies a visited hyperlink in web browsers?

The color that typically signifies a visited hyperlink in web browsers is purple. This convention is widely accepted in web design and user interface design. When a user clicks on a hyperlink, it often changes from blue (the standard color for unvisited links) to purple to indicate that the link has already been visited. This color change helps users navigate more effectively by allowing them to differentiate between links they have already explored and those they have not.

Other colors listed, such as red, gray, and green, do not generally have any specific or widely recognized meaning in the context of visited hyperlinks. While they may be used in custom web designs, they do not follow the traditional conventions established within web standards for hyperlink colors. Therefore, purple is the correct choice based on its established significance in web design practices.