[rangibaby]

You got it! While there isn't a "Swiss palette", bright and contrasting colors were popular for both technical and stylistic reasons:

"The following points must be considered whenever it is planned to use colour: the effect on the viewer, its usability in the various advertising media and the technical possibilities of reproduction.

The sparing, but methodical and logical use of colour has a more telling effect than a combination of many different colours. If colour is used, it should be plainly visible and the reasons for its use immediately apparent."

- Josef Müller-Brockmann The Graphic Artist and His Design Problems (1961)

which is a good book even now, it's a practical guide with plenty of examples, so you can get a good look inside his head, even if you don't necessarily agree with everything he wrote.