In the 1990s, Ellsworth Kelly's art continued to evolve in both form and complexity, demonstrating his enduring influence and innovation in the realm of abstract art. This decade is characterized by Kelly's further exploration into the possibilities of relief, a motif he expanded upon with notable works such as "Red Diagonal" (2007), even though the work was completed later, it exemplifies the direction Kelly was exploring during the 1990s. This piece, with its striking geometric construction and layered canvases, echoes his earlier exploration of panels and extends the visual and physical space of the viewer​ (The Art Story)​. Kelly's dedication to exploring the relationships between color, form, and space can be traced back to his early years, marked by a deep engagement with nature and a keen observation of his surroundings. These early influences, from birdwatching to his study of camouflage during his military service, informed his unique approach to art. His work, characterized by an abstract simplicity and a focus on the essential qualities of form and color, continued to evolve throughout his career​ (www.wikiart.org)​. During the 1990s, Kelly also created a series of large-scale, monochrome painted canvases known as Curves, exemplified by works such as "Yellow Curve" (1996). These pieces featured singular, large-scale shapes, each with one curved side, continuing his interest in simple yet powerful forms that began with earlier pieces. The Curves series represented Kelly's ongoing exploration of shape and form, utilizing monochromatic color to emphasize the purity of the form​ (www.wikiart.org)​. Kelly's art, always pushing the boundaries of minimalism and abstraction, remained grounded in a deep observation of the world around him. Whether in his large-scale sculptures, his exploration of the relief form, or his singular color fields, Kelly's work in the 1990s and beyond reflects a singular vision—one that continually sought to strip down to the essence of visual experience​ (Encyclopedia Britannica)​​ (The Art Story)​. Ellsworth Kelly's contributions during this period underscore his position as a pioneering figure in American art, whose work bridges the gap between the natural world and abstract expression, offering viewers a unique and contemplative visual experience. His legacy is a testament to a career spent exploring the nuances of visual perception and the transformative power of simplicity and form.