fillColor

Fillcolor is a term used in computer graphics to describe the color used to fill the interior of a shape or region. It is typically specified separately from the color used to draw the shape's outline (the stroke), allowing designers and programs to control fill and border independently.

Fillcolor can be expressed in multiple color models and formats, including named colors, hexadecimal RGB values, and functional representations such as RGB or RGBA. The alpha channel in RGBA enables transparency, letting the fill blend with the background or underlying layers. Some systems also support additional color spaces or gradients as fill definitions.

In common graphics systems, fill color is a property or attribute of shapes and graphics primitives. SVG uses the fill attribute; canvas operations use fillStyle; many plotting libraries refer to this as facecolor or color for filled regions. In document preparation and drawing tools such as LaTeX TikZ or Matplotlib, the fill color can be set globally or per-element and may be combined with patterns or gradients.

Patterns and gradients extend solid fills by shading within the interior. A fill can be a gradient transition, a hatch pattern, or an image fill, depending on the toolkit. Some environments allow complex fills that interpolate between multiple colors to create smooth transitions or textured appearances.

Practical considerations include choosing colors with sufficient contrast against surrounding elements, ensuring consistent rendering across devices and print media, and applying color management to maintain visual fidelity. Fillcolor remains a fundamental concept across vector graphics, UI design, and data visualization.