1986 (July)
Initially sold for ¥464,000
The Yamaha DX7 II-C (Centennial) is a limited edition DX7 II-fd, released in 1987 to be a "visual and musical celebration" of Yamaha's 100th anniversary. Apparently, 100 units have been made, but it's not so uncommon to find on sale.
The synthesizer is housed in a silver coloured casing, and all of the wheels, buttons and sliders are gold coloured (it's unclear whether they're just gold coloured or actually gold plated). Instead of the 5-octave, C-to-C keyboard that is standard to the rest of the DX7 line, the Centennial features a full 76-note keyboard (with an E-to-G range, the same as the KX76 MIDI keyboard controller). Finally, the keys of the Centennial have been specially treated: fluorescent paint has been mixed in with the plastic of the keys, so that the entire keyboard glows in the dark.