USB Mouse balls (OEM replacement, 1998)

The original Apple USB Mouse, model M4848, used a half-teal blue and half-white ball that matched the Bondi blue iMac. When new iMac colors were introduced (blueberry, strawberry, lime, tangerine, and grape) the teal and white ball continued to be used until it was replaced with a gray and white ball.

These teal and white USB Mouse balls are official replacement parts provided by Apple.

USB Mouse (tangerine, OEM part, M4848, 1998)

The Apple USB Mouse was first released with the original iMac. The mouse was translucent white and accented in translucent Bondi blue, the same colors as the original iMac. The mouse was round and often referred to as the “hockey puck” mouse. Like previous Apple mouse designs, the USB mouse used a single button and a rubber ball for tracking. However, the rubber ball was two-toned to add design interest by capitalizing on the translucent case.

The mouse has been described as a rare design mistake for Apple because its round shape made it difficult to feel the top of the device, making tracking difficult. Soon after its release, Apple added a dimple in the graphite version of the mouse at the top above the button. The dimple remained on all subsequent versions of the USB Mouse, including this example.

This tangerine mouse was not shipped with an iMac. Instead, this mouse was an OEM replacement part that was shipped in a utilitarian plastic bag rather than retail packaging.

The mouse also had a short cord. Although the cord worked well when plugged into the USB port on a matching iMac keyboard, the cord was too short to use (for right-handed users) with Mac laptops at the time since USB ports were located on the left side. 

Source: Wikipedia.com