The Color Computer was interesting. They kept the 8-bit fire burning a little longer than was truly reasonable, but I wouldn't fault them for it.

The 6809-based Color Computer was my first computer and it was indeed incredibly powerful. Unfortunately, all that power was in the CPU itself, arguably the best 8-bit CPU ever made (because it was really an 8-bit / 16-bit hybrid) and the 68000's immediate predecessor.

Tandy just used the Motorola reference design so there was nothing unique or proprietary to Tandy. The graphics were just a straight bitmap from CPU RAM, no sprites, tiles, or selectable palette colors. The sound output was a plain six bit DAC that had to be driven by the CPU on interrupts.