pxt-common-packages/libs/game/docs/reference/images/image/replace.md

Microsoft MakeCode (PXT) common packages

# replace

Replace all the pixels of one color with pixels of another color.

```sig
image.create(0, 0).replace(0, 0)
```

## Parameters

* **from**: the color [number](/types/number) of the pixels to change.
* **to**: the color [number](/types/number) of the replacement pixels.

## Example #example

Make a square of random colors, then randomly replace the colors until the square becomes just one color.

```blocks
let colorBlock = image.create(32, 32)
for (let y = 0; y < 32; y++) {
    for (let x = 0; x < 32; x++) {
        colorBlock.setPixel(x, y, Math.randomRange(0, 15))
    }
}
let showBlock = sprites.create(colorBlock)
game.onUpdateInterval(500, function () {
    colorBlock.replace(Math.randomRange(0, 15), Math.randomRange(0, 15))
})
```

## See also #seealso

[fill](/reference/images/image/fill)