Replace Color in Image

This tool finds every pixel of one color in a picture and changes it: recolor it to a new color, make it transparent (for example to remove a plain background) or keep only that color and clear everything else. Colors are compared in the OKLab color space, so the tolerance behaves the same for light and dark colors, and the shading option keeps highlights and shadows when you recolor an object. Everything runs in your browser — your images are never uploaded.

How to use this tool

1. Choose one or more images (PNG, JPG, WebP, GIF…).
2. Type the color to find, or keep "auto" to use the most common color (usually the background).
3. Pick an action and, for replacing, the new color.
4. Raise the tolerance and soft edge until the edges look clean, then download the PNG.

Formula

distance = 100 × √((L₁ − L₂)² + (a₁ − a₂)² + (b₁ − b₂)²) in OKLab · weight = 1 if distance ≤ tolerance, falling to 0 across the soft edge

With shading on, each matched pixel keeps its own offset from the found color: new = target + (pixel − found), all in OKLab, so darker and lighter parts of the object stay darker and lighter. Black to white is a distance of 100.

Example

With the found color #2563EB and tolerance 8, a pixel of exactly that blue is replaced completely by the new color — red #FF0000 stays #FF0000 — while an orange pixel such as #F59E0B, about 50 units away, is left untouched. With "Make it transparent", the same blue pixels get alpha 0 and the PNG keeps the rest.