Immediately after importing, the newly imported records form your current found set.
Replace Field contents can modify data in a field for every record in your found set.
If you use the calculation option with the TextColor and RGB functions, you can apply a text color to the text in the field for every record in your found set.
Replace field contents and these functions can be looked up in FileMaker Help if they are unfamiliar. It's a good idea to first save a backup copy of your file when experimenting with Replace Field Contents as this can change the data in large numbers of records all in one go.
I do not want to replace the text colour for a field for every record.
I want to change to exisiting default text format colour for any changes I make after data is imported. Everytime I make a change I have to change the text colour as it always reverts back to the default. It would save time to not have to make this change each time.