  Double parton distributions satisfy the same evolution equations as ordinary
single-parton densities, provided that the colours of the two partons are
uncorrelated. The situation is different for colour correlated parton pairs,
where evolution to higher scales results in a suppression by Sudakov double
logarithms. We perform a detailed study of evolution for colour correlated
double parton distributions, both analytically and numerically, at lowest order
and beyond. When the two observed partons originate from the perturbative
splitting of a single one, the Sudakov suppression of colour correlations at
the cross section level is not as strong as one might expect.
