  Generating temporally separated two X-ray pulses or even two pulses with
different colors has been pursued for various X-ray experiments. Recently, this
concept is extended to generate multi-color X-ray pulses, and a few approaches
have been proposed. We introduce one of possible new ways to generate
multi-color X-ray using a longitudinal phase space (LPS) modulator and a
manipulator. In this example, a wakefield structure and double-emittance
exchange beamline are used as the LPS modulator and the LPS manipulator,
respectively. In this way, we can generate multiple bunches having designed
energy and time separations. These separations can be adjusted for each
application differently. This paper describes the principle of the method and
its feasibility.
