Generally used classes by Daniel Nilsson. ColorPickerPreference class by Sergey Margaritov. Packed by Sergey Margaritov.

• Color Area
• Hue Slider
• Alpha Slider (disabled by default)
• Old & New Color
• Color Preview in Preferences List

Tested with APIv7, but maybe will work with early versions

You can see some tests inside

<net.margaritov.preference.colorpicker.ColorPickerPreference
    android:key="color1"
    android:title="@string/color1_title"
    android:summary="@string/color1_summary"
    android:defaultValue="@integer/COLOR_BLACK"     <!-- HEX value also accepted (v1.1) -->
    alphaSlider="true"                              <!-- enable alpha slider via XML -->
/>

To enable Alpha Slider in your code use function:

setAlphaSliderEnabled(boolean enable)