---
title: bg-color
summary: null
url: https://www.fastly.com/documentation/reference/io/bg-color
---

Sets the background color of the image.

The `bg-color` parameter sets the background color of an image to use when applying [padding](https://www.fastly.com/documentation/reference/io/pad) or when replacing transparent pixels.

## Syntax

```text
bg-color={value}
```

`value` may be one of:

- **Hex RGB value**: Both 3- and 6-digit values are acceptable (e.g. `a22` or `cf23a5`).
- **Decimal RGB**: RGB values between 0 and 255. Comma-delimited (e.g. `255,0,0`).
- **Decimal RGB with alpha**| RGBA colors include an additional value for alpha (transparency), which ranges from 0 for fully transparent to 1 for fully opaque.

## Examples

Click the links to view the transformed image using a demo Fastly IO service.

| Example usage                                                                   | Description                                         |
| ------------------------------------------------------------------------------- | --------------------------------------------------- |
| [`?bg-color=c5c5c5`](https://www.fastly.io/image.png?bg-color=cccccc)           | Set background color to grey                        |
| [`?bg-color=000`](https://www.fastly.io/image.png?bg-color=000)                 | Set background color to black                       |
| [`?bg-color=0,255,0`](https://www.fastly.io/image.png?bg-color=0,255,0)         | Set background color to green                       |
| [`?bg-color=0,255,0,0.5`](https://www.fastly.io/image.png?bg-color=0,255,0,0.5) | Set background color to green with 50% transparency |