Although Riley is often associated with Op Art due to the optical effects within her compositions, her work extends beyond simple illusion. Rather than deceiving the eye, Riley’s works examine how colour and shape are perceived and how they function spatially. She eliminates all forms of representation, reducing visual language to its most essential elements: line, shape, and colour. In the stripe works particularly, Riley removes all unnecessary imagery, allowing the repeated bands to become a framework through which she can explore the complexity and variability of colour relationships.
In Rose Horizontal, as suggested by the title, Riley focuses on warm hues of peach, pink, and orange, creating an atmosphere of softness and warmth. These tones are interrupted by delicate yet striking flashes of light blue and zinging green, producing moments of sharp visual contrast. As the viewer’s eye travels down the horizontal bands, each adjacent colour alters the perception of the next. A single peach tone, for example, appears to shift in intensity depending on whether it is placed beside a vivid green or a muted orange. Riley therefore demonstrates how colour is never fixed, but constantly transformed through context and interaction.
Rose Horizontal is unusual in its horizontal form, most often we see Riley reflect the human eye's propensity to read works left to right. Here we are challenged by reading a single band horizontally and instead the bottom to top bends and shifts lengthening and shortening our experience of the visual field.
The repetitive structure of the stripes encourages sustained visual engagement. Because the composition is built from a seemingly monotonous form, the viewer becomes increasingly aware of subtle chromatic variations and rhythmic shifts across the surface. The work appears to shimmer and pulse as the eye traverses the painting, creating a sense of movement and instability despite the strict geometric order of the composition.
