It was designed before MIDI and featured a 25-pin D-sub connector computer interface used to slave the Expander to the Chroma.

The Chroma has sixteen synthesizer "channels" each consisting of one oscillator, waveshaper, filter and amplifier.

The embedded computer generates thirty-two ADSR envelopes (two per channel, one with delay) and sixteen LFO sweep signals in software.

This yields two oscillators, two waveshapers, two filters, two amplifiers, two glides, two LFO sweeps, and four ADR envelopes, in addition to the performance controls.

[13] Each configuration connects (or patches) the oscillators, filters and amplifiers together in different ways to provide for a wide variety of possible sounds.

The Chroma's economical approach to control panel design was copied by many later synthesizers like the Yamaha DX-7.

In 2008,[8] a third party designed and produced a digital switching power supply replacement kit.

[14] The main microprocessor in the Chroma and Expander is a 68B09, and it has a computer interface consisting of a 25-pin D-sub connector.

The factory original Chroma CPU board has 2 AA batteries to preserve memory while the power is off.

An Apple IIe interface card (used to connect to the Chroma's D-sub connector) and sequencing software was released by ARP and Fender Rhodes.

The dual footswitch is a rugged, heavy, solid piece of hardware that mimics a pair of standard piano foot pedals with programmable functions including sostenuto.

The Chroma also came with a custom designed, heavily padded, ATA Anvil (R) case with a pedal compartment.

Like the Chroma, the main microprocessor in the Expander is a 68B09 with a computer interface consisting of a 25-pin D-sub connector.