Agnes Martin's late career, particularly "Homage to [a] Life: Paintings 1990-2004," showcases a reflective and exploratory phase in her artistic journey. This series highlights Martin's continued experimentation within the confines of her minimalistic style, marked by a subtle yet profound use of color and form. During this period, Martin's work featured pale pinks, blues, and lemons applied in horizontal bands, sharply delineated with graphite lines. As the decade progressed, these hues evolved into richer apricots, salmons, and other vibrant colors, demonstrating her unceasing innovation in the use of minimalistic elements to evoke emotional and spiritual responses (Dia Art Foundation) .

In her later years, particularly noted in her work from the early 2000s, Martin introduced changes in her artistic vocabulary. This included a brief period where she experimented with more opaque and dense forms, moving away from her characteristic luminous washes. Her works during this time, such as "Little Children Loving Love" (2001), displayed a vertical structure that was new to her usual format. This period was also characterized by a shift towards darker, more monochrome palettes, which marked a significant thematic departure as she began to explore more somber and introspective themes (Dia Art Foundation).

Her work remained deeply imbued with a spiritual and philosophical depth, reflecting her lifelong quest to express the ineffable qualities of human experience through abstraction (Dia Art Foundation).

This late career period stands out as a testament to Martin's enduring commitment to exploring the potential of minimalism to convey complex emotional and spiritual states, further solidifying her legacy as a pivotal figure in modern and contemporary art.