The RBe 4/4 were originally lettered SBB CFF/SBB FFS without the Swiss crest.
At some point in the 1980s, a number of these railcars were adorned with the new SBB logo (Pleitegeier) <+> SBB CFF FFS
At some point, probably around 1990, a number of these railcars had the ends painted red.
Around the same time, a small number of these railcars had one end painted in a special orange/yellow livery for use on the Seetal Line (Luzern - Lenzburg)
In the mid-1990s, a number of these railcars were repainted in the Regio (NPZ) livery. A few years later, the railcars were modified again as the original doors were replaced by flush swing doors, as were the carriages.
Around 2000, it became common to see push-pull trains with a RBe 4/4 (540) at either end of the consist, rather than a single motor unit with a pilot coach.
This freed up a number of pilot coaches for use with Re 4/4II in Regio and Interregio consists.