Hi,
Various people have already mentioned Mark Hill's book, Czech, Novy Bor (where it was probably made) and the 'Dual' range, but, unless I need those new glasses quicker than they are already being made, no-one has mentioned the probable designer - Karel Wunsch.
As soon as I looked at your photo, that was my first reaction, and would be where I would be looking for an attribution for this really good looking bowl. If it is the Dual rang, then it is early 1960's, but Mark also talks about the 'Trial' range which was similar, but with three colours. Could also be form the series when it appeared to widen out using more shapes, and designers, in 1971. Other designers of the series at that point include J Stahlavsky and Jiri Kratochvil. See also page 20 of the book.
Nigel