  We present a method to measure the spectrally-resolved transmission matrix of
a multiply scattering medium, thus allowing for the deterministic
spatiospectral control of a broadband light source by means of wavefront
shaping. As a demonstration, we show how the medium can be used to selectively
focus one or many spectral components of a femtosecond pulse, and how it can be
turned into a controllable dispersive optical element to spatially separate
different spectral components to arbitrary positions.
