Facecolor

Facecolor is the color used to fill the interior area of a polygon, patch, or other geometric primitive in computer graphics and data visualization. It is typically contrasted with the edge color (edgecolor), which colors the boundary. In plotting libraries, the facecolor determines how the interior of a shape appears; the value can be a named color (for example, blue), a hexadecimal color code (#1f77b4), or an RGB/RGBA tuple, where the alpha channel controls transparency. A facecolor of none or "none" indicates a transparent interior.

In practice, many environments expose a facecolor property on shape objects such as patches (rectangles, circles, polygons) or on color collections. The facecolor can be uniform for a single shape or specified per-face for multi-faced objects. Some libraries use the plural facecolors for collections. Defaults are often defined by a style or configuration, such as rcParams in Matplotlib.

In 3D graphics and shading, face color refers to the color applied to the visible surface of a polygon, possibly modified by lighting and material properties.

When using a library like Matplotlib, common usage includes setting the facecolor of a shape with a specific color value or adjusting global defaults for all shapes. See also edgecolor, color, and RGBA color specifications.