Amid the shifting tides of artworld influence and reaction, signature paintings by Frederick Hammersley and Larry Zox, two leading historic figures in the geometric and color-field abstraction movements, offer pure, fresh visual pleasure.

Nearly half a century has passed since Jules Langsner included Mr. Hammersley in the 1959 landmark exhibition “Four Abstract Classicists.” Along with Lorser Feitelson, Karl Benjamin, and John McLaughlin, who were also working in Los Angeles in the 1950s, Mr. Hammersley has been credited with inventing the style that came to be known as “hard edge” or “abstract classicism.” The exhibit, first seen at the San Francisco Museum of Modern Art, traveled to the Institute of Contemporary Art in London, where the critic and curator Lawrence Alloway added “West Coast Hard Edge” to the title.

On view now at Ameringer & Yohe is a group of Mr. Hammersley’s classic abstractions that date between 1960 and 1992. Mediumsize square and rectangular paintings feature one, two, or three colors, plus black, white, or both black and white. Simple geometric shapes are arranged to create dynamic, expressive effects and fields of full color whose edges abut crisply, yet show traces of the hand.

Some of the works seem to favor the figure (albeit abstract) and others the ground, but in many cases the images straddle the liminal zone between them. Mr. Hammersley’s vibrant, expressive colors are carefully calibrated but never become optical tricks. Evocative, witty titles are carefully chosen from a collection of words the artist keeps in a notebook. In “Enter” (1962), black, white, and green shapes are organized within a subtle vertical grid, four tall and three wide. On the right third of the image is a slick black band which recalls a wall cast in shadow. In the remaining two-thirds, a flat, white plane with a diagonal slot tilts upward as if in full sunlight, into which a green daggerlike shape enters. Mr. Hammersley’s paintings do not have narrative content, but they often inspire associations. His skillful combination of language, design, and color allow this green, for example, to bring to mind all things vegetable-, forest-, and sea-like, but this can also quickly slide toward the mineral, like a shimmering emerald.

***

Larry Zox, who died in December at age 69, was a highly visible figure in the post-painterly, colorfield abstraction movement of the 1960s. He is best known for his colorful, heraldic, geometric abstractions of that time. In a memorial exhibition at Stephen Haller, his subsequent works spanning four decades reflect his overlapping and interfused painterly concerns.

Many of the key pieces on view are from his “Gemini,” “Diamond Cut,” and “Scissor Jack” series. In their smooth, unmodulated planes of color and flattened geometric compositions, these works reflect the reactionary attitude Zox shared with peers such as Kenneth Noland and Frank Stella toward the Abstract Expressionists of the previous generation.

Most of these are intensely hued, refreshingly large, clear statements that reflect Zox’s fine-tuned focus on form and color. There are also a few small gems such as “Untitled Study,” in colored pencil on graph paper and “Beach,” a small acrylic on rag board. Both made in 1964, they allow us a rare glimpse of the artist’s hand and thought processes. “Beach” is from the “Rotation” series and resembles a flattened pinwheel. Two thin black bands framed with coral, red, and yellow horizontally span a grayblue field. White and yellow wedge shapes at the perimeter suggest rotation. Its uneven paint and visible brush marks belie its provisional nature.

Far back in the gallery is “Untitled” (2006), one of Zox’s last paintings, measuring 61 inches by 59 inches. It is impressive to consider, although fighting cancer, he continued to explore new ideas and to extend his visual language. A few strategically placed patches of black and red punctuate vertical skeins of muted teal, coral, impure yellows, and oranges. The colors appear close to the surface and free of all hard-edge strictures. They seem to sway and flow, while a few thin lines of intensified color linger tentatively, as if caught in a breezy dance.

Hammersley until February 10 (20 W. 57th St., between Fifth and Sixth avenues, 212-445-0051);

Zox until February 27 (542 W. 26th St., between Tenth and Eleventh avenues, 212-741-7777).