How do I change one color in a graphic without affecting similar colors elsewhere?

Separate the task into two steps: identify the exact area, then apply the color change only there. In GIMP, Fuzzy Select selects areas according to color similarity, and its threshold controls how broad the match is. Results also depend on where you start and on the image, so treat the selection as a first pass to inspect—not a guarantee that every selected pixel belongs to your object. [S1]

For example, suppose you want to recolor a blue emblem on a poster but leave blue lettering alone. Start inside the emblem with Fuzzy Select and inspect the highlighted region. If the lettering is included, or parts of the emblem are missed, refine the selection before changing color.

Inspect the selection around the object’s outline and check for both missed parts inside the object and selected pixels in the nearby background or similar-colored details. Refine the selection rather than accepting a broad match just because the main area looks right. Selection results vary with the starting point and image; there is no single threshold established here for every graphic. [S1]

Ask yourself: “If I changed the selected region now, would every affected part be something I intend to recolor?” If not, keep refining. You can also try another selection tool if a color-based selection is not precise enough; the GIMP guidance notes that Fuzzy Select may be less precise than other selection tools. [S1]

Keep the adjustment limited to the active selection. In GIMP, Color Balance can affect the active selection or the active layer, so check that the intended selection is active before adjusting. Its controls cover shadows, midtones, and highlights. Preserve luminosity is an option for maintaining brightness while adjusting color. [S2]

For a more editable boundary, use the selection to initialize a layer mask on a separate adjustment layer. Selected areas become opaque in the mask, unselected areas transparent, and partial selections retain partial values. The mask controls where the layer shows through, letting you refine the boundary without directly erasing image pixels. [S3]

For the emblem example, the adjustment should show on the emblem, not the lettering. If the initial selection included stray areas, refine the mask boundary.

Use this sequence, adapting tool names to your editor:

1. Select the intended object. With GIMP Fuzzy Select, start inside it and adjust the threshold with the understanding that it controls how broad the color match is. [S1]
2. Inspect the whole selection, especially its edges and any similar-colored details elsewhere. Refine it or try another selection tool if needed. [S1]
3. Confine the adjustment with a mask initialized from the selection, rather than applying a broad change to the whole image. [S2] [S3]
4. Adjust the color and review the boundary. In GIMP Color Balance, consider the shadows, midtones, and highlights controls; use Preserve luminosity if maintaining brightness matters. [S2]
5. If unrelated areas are affected, correct the selection or mask before continuing.

These steps describe the cited GIMP tools and mask behavior; other editors may use different tool names or workflows.