  We present a Hubble diagram of type II supernovae using corrected magnitudes
derived only from photometry, with no input of spectral information. We use a
data set from the Carnegie Supernovae Project I (CSP) for which optical and
near-infrared light-curves were obtained. The apparent magnitude is corrected
by two observables, one corresponding to the slope of the plateau in the $V$
band and the second a colour term. We obtain a dispersion of 0.44 mag using a
combination of the $(V-i)$ colour and the $r$ band and we are able to reduce
the dispersion to 0.39 mag using our golden sample. A comparison of our
photometric colour method (PCM) with the standardised candle method (SCM) is
also performed. The dispersion obtained for the SCM (which uses both
photometric and spectroscopic information) is 0.29 mag which compares with 0.43
mag from the PCM, for the same SN sample. The construction of a photometric
Hubble diagram is of high importance in the coming era of large photometric
wide-field surveys, which will increase the detection rate of supernovae by
orders of magnitude. Such numbers will prohibit spectroscopic follow-up in the
vast majority of cases, and hence methods must be deployed which can proceed
using solely photometric data.
