Feature Request: Color Picker Alpha Slider

We're starting to use the Color Picker component controls in my app. We're using SpectrumSlice and SpectrumSlider and they're working great.

Could you add support for alpha channels to the color picker and add an AlphaSlider component? Or is there a way we can just use SpectrumSlider and change the way that it is rendered? Maybe with a custom style?

Thanks.

Bryan