Function colorParameter

colorParameter(color): ParameterExpression<Color>
Creates a new parameter expression. The difference with color is that you can change the value of a parameter later on, and the styling will be updated to reflect the new value without having to re-create the expressions in which it is used. Only colors may be used as value.
```
  var parameter = ExpressionFactory.colorParameter("rgba(47, 83, 127, 1)");
  ...
  parameter.value = "rgba(255, 255, 255, 1)";//Only ever assign colors.
```
Parameters
- color: string
  The initial value of the parameter, represented by a CSS color string.
Returns ParameterExpression<Color>
A color parameter expression.