Multi-select fields: Edit an option

There’s no automated way to do this, unfortunately. Your best bet might be to make a backup of your database, dump it, and then do a find and replace on the values involved. In the future, consider abstracting any lists/values like this that may require changing, e.g. instead of a manually defined dropdown, instead use a MySQL query, or instead of storing a value that might change, instead store the a value that does not, and do the conversion in the view layer (i.e. your template), e.g. store “red” in your dropdown and then put code in your templates to convert red to whatever color code you need. That way you wouldn’t break your associations when you change your value. This is more a question of data-modeling best practices than it is of the CCTM.