DLP should use default Java `java.awt.Color` class and not redefine a `Color` class with limited functionalities

```
ImageRedactionConfig imageRedactionConfig = ImageRedactionConfig.newBuilder()
          .setInfoType(infoType)
          .setRedactionColor(Color.newBuilder().setBlue())
          .build();
```

`setRedactionColor` takes in a custom `com.google.privacy.dlp.v2beta1.Color.class` : requiring the use of builders to set RGB values : 
This is a painful user experience.