Colored multipurpose printer paper and cover stock differ primarily in weight, thickness, and intended use. 
Colored multipurpose printer paper is typically lighter, usually ranging from 20 to 24 pounds in weight. It is designed for everyday printing tasks, such as documents, flyers, and memos. This type of paper is versatile and can be used in most printers and copiers. It comes in various colors, which makes it suitable for color-coding or adding visual interest to printed materials. The paper is generally smooth, allowing for clear text and image reproduction.
Cover stock, on the other hand, is heavier and thicker, often ranging from 65 to 110 pounds. It is also known as cardstock and is used for more durable applications, such as business cards, postcards, report covers, and invitations. The thickness of cover stock provides a sturdier feel and a more professional appearance. It can have different finishes, such as matte, glossy, or textured, which can enhance the visual appeal of printed materials. Due to its thickness, cover stock may require special handling in printers and may not be compatible with all types of printing equipment.
In summary, the main differences lie in their weight, thickness, and usage: colored multipurpose printer paper is lighter and used for everyday printing, while cover stock is heavier, thicker, and used for more durable, professional applications.