Other Chromatic Chords
For each degree of the scale, it is possible to build a major, minor, diminished and augmented triad. So, for example in C major, it is possible to use chromatic chords of C minor, C diminished and C augmented, D major, D diminished and D augmented, and so on.
In addition to this, the root of a triad can be altered, which gives us for example C# major, C# minor etc., and we can of course create 4 note chords as well.
All this means the total number of available chords is enormous. In practice though, some chromatic chords are much more common than others.
In this extract from a Beethoven Bagatelle in C major (WoO54), D#°7 is used as a chromatic passing chord. The chord notes are D#-(A)-F#-C. The soprano moves down chromatically through E-D#-D, and the tenor moves down through G-F#-F. The D#°7 sits between chord Ia and V7 (with a tonic pedal).
The beginning of the Alla Polacca from Reinecke’s Sonatina op.136 no.1 in C major, includes two augmented chromatic auxiliary chords:
Chord V+ is G-B-D#. The alto part moves chromatically by step from E to D#, then back again. Chord I+ is C-E-G#, and here the soprano part moves chromatically by step from A to G# and back. These are auxiliary chords because they are between two identical chords (I-V+-I and vib-I+-vib).