The Color Turbo is an enhanced NeXTstation. The features of the Color Turbo NeXT are:

The biggest advantages of the color turbo slab are the color display, increased memory capacity, and faster processor. It is possible to upgrade the color turbo using the very rare Nitro accelerator, which is a 40 mHz 68040 with 128k of cache. It is rumored that approximately twenty of these exist, though the number may be even lower than that these days. I don't have one of those, but I wish i did.