Trying to concat two field values together, using Concat I can do this. But now, trying to add : between the two field values and get an error: CONCAT({name}, : ,{displayname}) Using formula (text). Any suggestions

put the colon in quotes

That's actually how I initially had it, with quotes. Invalid expression error.

I think you can CONCAT 2 "data" at a time. Your example seems to be 3 separate strings to me. Try nesting 2 CONCATs. CONCAT(CONCAT({name}, ':'),{displayname})

Perfect, the double concat worked

You can also use the double-pipe to concat (the vertical line: || )