Once one digital colorway with a separator in the file name is created, by default it is restricted to be updated when importing the same file for the second time. This colorway cannot be published if already exists with the same name. You must change the file name and publish it again. 

But, if you want to skip the restriction, contact your neoCatalog administrator to enable modifications of colorways in the advanced preferences. This will display the 'Send file' button in the 'Edit Colorway' dialog to upload and replace the colorway file.

Related articles:

Enable Modifications of Colorways (advanced)

New digital colorway from import