These dark grey Daleks appeared several times. They first appeared in Day of the Daleks under the command of a gold coloured Dalek.
Day of the Daleks was the first TV story to feature the Daleks in colour.
Newly painted Daleks appeared in Genesis of the Daleks under the command of Davros. Later in Destiny of the Daleks one of these Daleks had survived and appeared to be in command of some lighter grey Daleks.
These Daleks appeared in the following TV stories: Day of the Daleks (1972), Frontier in Space (1973), Planet of the Daleks (1973), Genesis of the Daleks (1975) and Destiny of the Daleks (1979).
Pictures above are from the TV story Planet of the Daleks
Pictures above are from the TV story Genesis of the Daleks
Pictures above are from the TV story Destiny of the Daleks
No-one can succeed, who opposes the Daleks.