Colour testing the Blackmagic Design Mini Ursa Pro using a colour line up test chart from X Rite and waveform monitors from Divergent Media.
It's important to know how the camera sees the colour information gathered through the lens. Every camera has it's own colorimetry characteristics and colour matrix processing and so they will all see the same colours slightly differently. In a world where we are often shooting material in high dynamic range (HDR) using a film log curve rather than a standard video log curve, it's even more important to be able to re-create a known, standard 'look' from the raw footage.
Knowing how the camera responds to colour as well as highlight and lowlight information helps the Director of Photography (DoP) know how to light and shoot a scene.
The more testing you can do with a camera the better. And if you are using different types of camera to shoot multiple angles or different scenes within a production and you need all the footage to match, then it becomes even more critical. When you are grading the footage and you can have created a 'look' that you like and you want this to be consistent across the production, then knowing what corrections to apply to the different cameras footage prior to applying the LUT for the actual 'look' that you want is crucial.
The science of colour, of colour capture, colorimetry, colour space and colour reproduction is a fascinating and much mis-understood area of television and film production.