  We present a study of the persistent X-ray emission from the low-mass X-ray
binary 4U 1636-53 based ont he entire archival EXOSAT ME data set. We per-
formed a homogeneous analysis of all five EXOSAT observations in terms of the
correlated rapid X-ray variability and X-ray spectral properties by means of
power spectra, and colour-colour and hardness-intensity diagrams, respectively.
Over the years we find similar patterns in the colour-colour and
hardness-intensity diagrams, but small shifts in their postions occur. We find
one case of an island-banana transition. On all but one occasion the
differences in colour are smaller than 5%. Between the two 'island state' data
sets, we find a shift of 8 % in the soft colour, which must be at least partly
intrinsic. Clear correlations are present between the X-ray colours (which are
governed by the mass accretion rate) and the power spectrum. With increasing
mass accretion rate the fractional rms amplitude of the power-law shaped power
spectral component that dominates the power spectra below ~1 Hz rises, while
the band-limited noise component at higher frequencies drops. The cut-off
frequency of the band-limited component increases whn its amplitude decreases.
This is reminiscent of the behaviour of black hole candidates in the low state.
