Due to its short production span, only a few official Dreamcast models were released. The primary models released in 1999 had a grey tint and a weaker and quieter system fan while the later models of 2000 were a light grey-white colored tint with a stronger system fan and a faster, louder laser disc reader. The later model disc drives did not feature faster load times, except it was needed for protection against piracy. Since some consumers noticed the CD-R and CD-RW discs would not load on these drives, was due to the disc burns at certain speeds. The discs will not load at all due to the laser passing the data with the optical lense twice instead of once to read the CD-Rs. The power light, like the Dreamcast logo in NTSC regions, was orange. In the PAL Regions, the logo was blue. This was changed to avoid a trademark dispute with the German video game/DVD publisher Tivola, whom already used an orange swirl as their company logo.
Some special Dreamcast models were released in certain regions. In North America, a limited edition black Dreamcast was released with a Sega Sports logo below the Dreamcast logo on the lid, along with matching Sega Sports-branded black controllers. Electronics Boutique offered a blue Dreamcast through its website. In Japan, Sega released many varieties of the system, including a pink Sakura Taisen version, and a Hello Kitty version released in 2000 in Japan which, due to its limited production, has become an extremely rare collector’s piece. The package contains a keyboard, controller, VMU, mouse, and a Hello Kitty trivia game. The console and accessories came in both translucent pink and blue in color with some printed designs.
Outside of the generations there werent any changes made. The color is just for the bundle it was released with.
Also you can buy just the shell.