# a

> Alpha component of the color (0 is transparent, 1 is opaque).

## Definition

* **Type:** Field
* **Namespace:** [UnityEngine](/engine/6000.6/script-reference/unityengine.md)
* **Assembly:** UnityEngine.CoreModule

```csharp
public float a
```

### Examples

```csharp
using UnityEngine;

public class Example : MonoBehaviour
{
    public Color color = Color.white;

    void Start()
    {
        color.a = 0.42f;
    }
}
```