Allocate a color for an image

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- PHP Manual
- GD and Image Functions
- Allocate a color for an image

# imagecolorallocate

(PHP 4, PHP 5, PHP 7, PHP 8)

imagecolorallocate — Allocate a color for an image

### Description

imagecolorallocate(
GdImage `$image`,
int `$red`,
int `$green`,
int `$blue`
): int|false

Returns a color identifier representing the color composed of the given RGB components.

imagecolorallocate() must be called to create each color that is to be used in the image represented by `image`.

> Note:

> The first call to imagecolorallocate() fills the background color in palette-based images - images created using imagecreate().

### Parameters

`image`

  A GdImage object, returned by one of the image creation functions, such as imagecreatetruecolor().

`red`

  Value of red component.

`green`

  Value of green component.

`blue`

  Value of blue component.

These parameters are integers between 0 and 255 or hexadecimals between 0x00 and 0xFF.

### Return Values

A color identifier or `false` if the allocation failed.

Warning

This function may return Boolean `false`, but may also return a non-Boolean value which evaluates to `false`. Please read the section on Booleans for more information. Use the === operator for testing the return value of this function.

### Changelog

Version | Description
--- | ---
8.0.0 | `image` expects a GdImage instance now; previously, a valid `gd` resource was expected.

### Examples

Example #1 imagecolorallocate() example

    <?php

    $im = imagecreate(100, 100);

    // sets background to red
    $background = imagecolorallocate($im, 255, 0, 0);

    // sets some colors
    $white = imagecolorallocate($im, 255, 255, 255);
    $black = imagecolorallocate($im, 0, 0, 0);

    // hexadecimal way
    $white = imagecolorallocate($im, 0xFF, 0xFF, 0xFF);
    $black = imagecolorallocate($im, 0x00, 0x00, 0x00);

    ?>

### See Also

- imagecolorallocatealpha() - Allocate a color for an image
- imagecolordeallocate() - De-allocate a color for an image