InterpolateCallback (Charba - J2CL and GWT charts library based on CHART.JS)

```
public interface InterpolateCallback
```
Callback interface to be defined to customize the color on ColorAxis.

Author:

Andrea "Stock" Stocchero

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`Object`	`interpolate(double normalizedValue)`	Returns a `IsColor` or `String` instance which is representing a color.

- Method Detail
  - interpolate
```
Object interpolate(double normalizedValue)
```
    Returns a IsColor or String instance which is representing a color.
    
    Parameters:
    
    normalizedValue - normalized value of the data set
    
    Returns:
    
    a IsColor or String instance which is representing a color