Well, just change this:
el( ColorPalette, {
value: props.attributes.paletteData[0],
onChange: updatePalette,
} )
to this:
el( 'div', {}, props.attributes.paletteData.map(
function ( value, i ) {
return el( ColorPalette, {
'value': value,
onChange: updatePalette,
key: 'color-' + i, // required
//...
} );
}
) )
I.e. Pass an array of elements as the third parameter:
el( 'div', {}, <array of elements here> )
Or am I not understanding you?