COLOUR FORGE
Image colour swapper by Chuffnugget
Image Drag & drop anywhere on the page to load an image. The “Original” panel will highlight when ready to drop.
Current file: No file loaded
From colour (picked)
To colour (with alpha)
Tolerance options

Untick to tune red, green, blue and alpha separately without stretching the page.

Each new mapping saves its own mode and stays in the priority list.

Original

⇧
Drop an image here …or use the file chooser above
100%

Result (live preview)

Result will appear here Load an image on the left to get started
  • Hover over the Original image to see a real-time preview on the Result side.
  • Click to place a marker and lock that colour into “From colour”. Click the same marker again to remove it.
  • Download result exports only the mappings you have actually added. The temporary live preview is not baked in unless you save it as a mapping first.
  • Mouse wheel to zoom either preview. Right-drag or left-drag either pane to pan both locked views, middle-click to reset zoom and re-centre.

Colour mappings

Each rule swaps one colour range to another. Mappings are applied from top to bottom, so higher items win on overlap. Click any tile to edit it, drag by the handle to reorder with animated sliding previews, then toggle, remove, undo, redo, or save everything as a .colourfile project.

    No mappings yet. Pick a from colour (via marker), a to colour (with alpha if you want), set tolerance, then hit Add mapping. You can save and reload full projects as .colourfile files, including the uncompressed source image. When mappings overlap, the one nearest the top wins.

    Online PNG and JPG Colour Replacer

    COLOUR FORGE is a free, browser-based tool for changing colours in PNG, JPG/JPEG, WEBP, GIF and BMP images. Replace one colour with another, recolour logos and icons, or tweak UI assets without installing any software.

    How This Image Colour Swapper Works

    1. Upload an image file or drag and drop it into the “Original” panel.
    2. Hover the original image to see a live preview of the colour swap on the result side.
    3. Click to place a marker and lock in the exact colour you want to replace.
    4. Choose the new colour (including transparency), adjust the tolerance, and add multiple colour mappings.
    5. Download the final result as a PNG with transparency preserved.

    Examples of Use

    • To help process images for HueForging – cleaning backgrounds, flattening colours, and tweaking contrast before generating 3D litho-style prints.
    • Recolouring logos and icons for dark mode / light mode without going back into heavy image editors.
    • Quickly updating UI assets in apps and games when brand colours change.
    • Making white or black areas semi-transparent or fully transparent for overlays and watermarks.
    • Experimenting with alternate colour schemes on stickers, badges, and simple pixel art.

    Keyboard Shortcuts

    Pan view
    ↑
    ← ↓ →
    Zoom
    + −
    Undo / redo
    Ctrl Z
    Ctrl Y
    Mappings
    Enter Add mapping (when in controls)
    Delete Delete focused mapping

    Shortcuts work when focus isn’t inside a text field or number input.