Sensors and methods

A capacitive fingerprint (skin) sensor 10 wherein each sensor pixel stack comprises: a thin film transistor (TFT), capacitor electrode 114 and a colour filter layer 14 to provide a coloured sensor surface. Reflective layers 21 may be located below the colour filter in the stack. The reflective layers may be a capacitive sensing electrode 114, shield layer 113 or any conductive component of the stack. The colour filter may be provided between a passivation layer 101 and a hydrophobic coating 103. The filter may provide a variable aperture ratio to the sensor pixels, where the ratio is determined by the transmissive middle section (311, Fig.3) of a filter and an opaque border section (312, Fig.3). The colour filter may compromise two filters of different colour. The filter may be backlit by a light source 22. The colour filter layer may be provided by a photolithography method.