Recoloring One Image Region While Preserving Its Shading

A global hue slider changes too much when only one part of an image should be recolored, such as an icon, logo, or flat background. The described method starts from a clicked seed pixel and grows a selection through 8-connected neighbors whose color and alpha fall within set tolerances. A second, looser pass captures anti-aliased edge pixels adjacent to the selection without leaking into distant areas. To keep highlights and shadows intact, the new color is scaled per pixel by luminance relative to the region's dominant base brightness, with alpha left unchanged. The approach is implemented in the recolor-region package, which works on raw RGBA bytes with no dependencies.