Adding multiple colorpickers to theme options page

I added an additional colorpicker (link background color) to twentyeleven’s options page. But it only works when I enter the hex code manually, the actual colorpicker seems to override the first colorpicker’s value.

Here is a screenshot.

It seems to be a javascript issue that can be solved somewehere in /twentyeleven/inc/theme-options.js but I don’t know how.

Any help appreciated!