Color can be measured by using a spectrophotometer which takes measurements in the visible region of the wavelength range.
An excellent method for measuring layer thickness is the use of white light interference.
Microscope spectroscopy focuses on small measuring spots. The smaller the structure the more difficult is the precise positioning of the sample.
NIR spectroscopy is a well-established technology for accurate online moisture measurement.
Near Infrared Spectroscopy
Reflectance and Transmittance