The problem is most likely with your data entry, not the sorting.
When a record is committed with no data and then you add the phone number you are not clearing the make red formatting.
I'm not sure why SortList was giving me the strange text color issue, but SortValues does work as expected. When I changed the functions in my calc, I accidentally deleted the List() function around my calc field. No problems with SortValues. Delivers the list as I expect to see it.
In case anyone is interested: