The jquery-simple-color plugin has received a bunch of callback-related goodness thanks to jbergen. He’s also added a live preview option which displays the currently-hovered-on color.
onSelect: Function to be called when a color is selected. The
hex code is passed into the function.
default value: null
onCellEnter: Callback function that excecutes when the mouse enters a cell.
default value: null
returns: hex value
onClose: Callback function that executes when the chooser is closed.
default value: null
livePreview: The color display will change to show the color currently
under the mouse. The display will revert if no color is
selected.
default value: false
If any of this sounds useful, go grab v1.1.3 now :)