I want to travel from Konstanz to Schaffhausen. The road they recommend me to take "Konstanz to Singen by RB 87694 train, Singen to Schaffhausen by IRE 3048 train". I would like to clarify if these trains are switzerland trains. If they are not switzerland trains, will they also be covered by the Swiss Travel Pass?
Also, to check, the tickets from Basel to Colmar is not included by the swiss pass?
Both trains (Konstanz to Singen and Singen to Schaffhausen) are German trains and they run through Germany. Therefore, your Swiss Travel Pass is not valid.
See this map for full details about the Area of validity: https://www.sbb.ch/content/dam/sbb/de/infotexte/uebersichtskarte-sts.pdf