What color measurement system would be best to define colors for a liquid, to be described in a US patent?
First, you would have to measure the spectral transmittance of a sample and define the measurement conditions such as the path length through the liquid that you are measuring. You could then do normal colorimetric computations with the measured spectral transmittance. You would have to select and appropriate illuminant and observer and then you could compute CIE XYZ and/or CIELAB coordinates to define the color.