I have a text field with a set of Key|Value pairs that I originally set arbitrarily, but now need to order/sort. I already have a hundred nodes using the arbitrary values, how an I reconfigure them all?

Original Required 
0|Blue
1|Yellow
2|Orange
3|Violet
4|Indigo
5|Green
6|Red
 
0|Red
1|Orange
2|Yellow
3|Green
4|Blue
5|Indigo
6|Violet

I think that if I make this change, then all the existing notes will have the wrong colour. So I think I need a way to update the values stored in the database. Is there a module that will help do this?