Article date: Sep 1978
Article title: Puzzling over a problem-solving matrix, cubes of many colors and three-dimensional dominoes
Mathematical Games column? Y
Book: 14. Fractal Music, Hypercards and More...: Mathematical Recreations from Scientific American Magazine
Chapter: 6. The Thirty Color Cubes
This data confirmed? yes
Notes
Peter Rowlett (27 August 2022):
Peter Rowlett initial guess (Uncertain)
Peter Rowlett (4 November 2023):
I have seen this chapter and column side-by-side and they match.