Atelier 17 printmaker Terry Haass did this color intaglio using scraping of the plate as well as open bite etching. The artist applied the colors in a single printing using different density rollers to apply the inks and letting the viscosities of the inks blend when printed. Haass was able to create chromatic works without aquatint using, etching with varnish resists and scraping.
According to Christina Weyl's biography on Haass in her 2019 book "The Women of Atelier 17", page 227: "From the 1960s onward, her work - still mostly graphics but with the addition of sculpture in stainless steel, wood, and Plexiglas - focused on time and space, influenced heavily by science and Albert Einstein's theories."
"Nexus VII" is from a series of prints created for the portfolio "Nexus", a series of 7 prints, that was co-published by Madeleine LacouriƩre in Paris; Bjerke Galerie, Oslo; Sylvan Cole, Jr, New York and Edizioni Scheiwiller in Milan. A "Nexus" is defined as a connected group or series.