I assume the Blue, red, green, purple, and black drive from western digital.
they each have slightly different performance goals. Black are the enterprise drives, long warranty, expected always running environment. built to excel in that environment.
Red are NAS drives, meant to be used in groups to increase the total capacity and redundancy. NAS stands for Network attached Storage, so these are built for that environment.
greens are eco, slower, have long spin up times.
purple are meant for surveillance/camera recording, again always on, not built for super speed but meant for constant writes and built expecting to write as the main function.
Blue drives are the consumer drives, although most enthusiasts prefer the longer warranty, better build quality, and reliability of a black drive
oversimplification but you should get the gist