---
id: fast-colors.computealphablend
title: computeAlphaBlend() function
hide_title: true
---
<!-- Do not edit this file. It is automatically generated by API Documenter. -->

[@microsoft/fast-colors](./fast-colors.md) &gt; [computeAlphaBlend](./fast-colors.computealphablend.md)

## computeAlphaBlend() function

Alpha channel of bottom is ignored The returned color always has an alpha channel of 1 Different programs (eg: paint.net, photoshop) will give different answers than this occasionally but within +/- 1/255 in each channel. Just depends on the details of how they round off decimals

<b>Signature:</b>

```typescript
export declare function computeAlphaBlend(bottom: ColorRGBA64, top: ColorRGBA64): ColorRGBA64;
```

## Parameters

|  Parameter | Type | Description |
|  --- | --- | --- |
|  bottom | [ColorRGBA64](./fast-colors.colorrgba64.md) |  |
|  top | [ColorRGBA64](./fast-colors.colorrgba64.md) |  |

<b>Returns:</b>

[ColorRGBA64](./fast-colors.colorrgba64.md)
