Concrete has been used for railway buildings since the 1920s, steadily increasing in its range of applications. Pre-cast traders' stores (eg. Ratio provender store), fencing, platforms, platelayers' huts and bridge girders all feature among the products of BRs' concrete works.
This will be a very useful colour for the many standard structures introduced by BR and for many non-railway lineside buildings from the 1950s and 60s.
18ml pot of water based acrylic paint.