Explanation:
The \(d\) block elements having unpaired electrons form coloured compound in \(CuF _2\) copper is \(Cu ^{++}\) state.
\(Cu ^{++}=1 s ^2, 2 s ^2, 2 p ^6, 3 s ^2, 3 p ^6, 4 s ^0, 3 d ^9 \text {. }\)
It has one unpaired electron. So, \(CuF _2\) is coloured compound.