Larger squares indicate those within 0.5arcmin of the RLAGN. The grey dashed line indicates the $3\sigma$ depth of the $J$ band. The best fit to the red sequence is shown by the red dotted line. The grey dotted line indicates 0.5mag below this line. The background greyscale shows the normalized distribution of the UDS for comparison. Spectroscopic members (Rettura et al., in preparation) are highlighted with large blue circles. [*[Bottom]{}*]{}: The quiescent fraction of galaxies in 7C as a function of $J$ band magnitude. Red squares show the cluster values, black diamonds indicate the quiescent fractions measured for field galaxies. []{data-label="fig:CMD"}](CMD_passivefraction.pdf){width="\columnwidth"}

![Observed $i'-J$ versus $J-[3.6]$ (rest-frame $U-B$ versus $B-J$) colour-colour diagram. The upper left quadrant selects quiescent galaxies at $z\sim1.6$. Sources further towards the upper-right are dusty star forming objects and those at bluer $i'-J$ colours are star forming galaxies. The background density map shows the expected normalized distribution of field sources from the UDS. The symbols are the same as in Figure \[fig:CMD\].[]{data-label="fig:UVJ"}](iJch1_UDS.pdf){width="\columnwidth"}

![The quiescent fraction measured in 4.5magnitude bins, which correspond to stellar mass bins. Red squares show the cluster values, black diamonds indicate the quiescent fractions measured for field galaxies. The top histogram shows the excess number 