Color: 16 bit

Apple, in an effort to hide their bits from public view, refers to 16-bit color as "thousands of colors" and 24-bit color as "millions of colors". When Macs became available with 32-bit color, it was also called "millions of colors". Leading to confusion and the joke of calling it "even more friggin colors". But Apple eventually eliminated the confusion by removing the option for users to change or discover their color depth.

RGB 565 means: 5 bits for red, 6 bits for green, and 5 bits for blue. The extra bit is assigned for green because of higher sensitivity to the color in human eye.