A device may include a sensor window. The sensor window may include a substrate. The sensor window may include a set of layers disposed onto the substrate. The set of layers may include a first subset of layers of a first refractive index and a second set of layers of a second refractive index different from the first refractive index. The set of layers may be associated with a threshold transmissivity in a sensing spectral range, and may be configured to a particular color in a visible spectral range and associated with a threshold opacity in the visible spectral range. The device may include a spectral sensor device aligned to the sensor window and including at least one sensor element to receive light in the sensing spectral range and provide a plurality of sensing functionalities based on at least one measurement of the light in the sensing spectral range.