TypeScript error - type not assignable?
I'm getting the following error when trying to pass the color from the state to the `SketchPicker` component, just like in the last example in [this page](http://casesandberg.github.io/react-color/#create-parent):

>  Overload 1 of 2, '(props: Readonly<SketchPickerProps>): SketchPicker', gave the following error.
    Type '{ r: string; g: string; b: string; a: string; }' is not assignable to type 'string | HSLColor | RGBColor | undefined'.
      Type '{ r: string; g: string; b: string; a: string; }' is not assignable to type 'RGBColor'.
        Types of property 'a' are incompatible.
          Type 'string' is not assignable to type 'number | undefined'.
  Overload 2 of 2, '(props: SketchPickerProps, context?: any): SketchPicker', gave the following error.
    Type '{ r: string; g: string; b: string; a: string; }' is not assignable to type 'string | HSLColor | RGBColor | undefined'.
      Type '{ r: string; g: string; b: string; a: string; }' is not assignable to type 'RGBColor'.

It errors here:

`<SketchPicker color={this.state.color} onChange={this.handleChange} />`

.. and following is the type of `this.state.color`, which I'm passing to `SketchPicker` in the lie above - isn't it the same object shape of `this.state.color` on the example [here](http://casesandberg.github.io/react-color/#create-parent)?

```
type Color = {
    r: string
    g: string
    b: string
    a: string
}
```

I don't understand. And where can I see the types mentioned here: `string | HSLColor | RGBColor | undefined'.`?


