The autoharp produces chords through a clever mechanical system: 36 chromatic strings are always present, and pressing a chord bar mutes every string that does not belong to the selected chord. When you strum, only the chord tones ring. ChordColor visualizes this by showing all 36 strings and highlighting which ones ring (with interval colors) and which are damped for each chord. This reveals the actual voicing that the autoharp produces -- a wide, harp-like spread of chord tones across three or more octaves.
The chromatic string layout means that every chord type is theoretically available, unlike diatonic instruments. However, physical autoharps have a limited number of chord bars (typically 12, 15, or 21). ChordColor is not limited by bar count -- you can explore all 528 chord types and see which strings each one uses. This is useful for understanding the harmonic possibilities of different autoharp models and for planning custom chord bar configurations.
Autoharp playing styles range from full strums (sweeping across all strings while a chord bar is pressed) to pinch picking (plucking individual strings for melody and accompaniment). The interval colors help pickers identify which strings to target for melody notes within a chord -- the root and fifth provide accompaniment stability, while thirds and sevenths add harmonic color to picked passages.