Colour accuracy is an odd term as no photograph truly recreates colours as they were in the original scene after all cameras, computer screens and prints have a much narrower gamut than what the eye sees. What is really meant by colour accuracy is buried in a lot of science and math. In the end, we are creating illusions or facsimiles of the place where we took the picture. In my view when we are rendering an image we are creating an impression of a moment in time, and so colour accuracy may not be as important as whether or not the image conveys what it was like to be in that moment, and how we interpreted what we were seeing. As John Berger put it: The way we see things is affected by what we know and what we believe... We never look at just one thing; we are always looking at the relation between things and ourselves. Our vision is continually active, continually moving, continually holding things in a circle around itself, constituting what is present to us as we are. So our photographs are a dialogue between ourselves and what surrounds us, and how we use colour is part of that dialogue.
We also need to keep in mind that we perceive colour differently as colour tests demonstrate. ( https://www.colorlitelens.com/color-blind-test.html ) These colour variations can be in up to 30% in some populations.
When rendering RAW colour images in programs like Lightroom, the image first appears in the develop mode defaulted to Adobe Standard “Profile.” This can be found just below the histogram at the top of the right-hand menu in the develop mode. Adobe Standard is designed to provide consistent colour rendering between different camera models. However, it may not necessarily provide colour accuracy for the particular camera you are using.
If you click on “Adobe Standard” you will discover there are a number of Adobe profiles to choose from each one designed for different types of photography. Choosing any one of these profiles will change the way in which colour is being represented in Lightroom. If you select “browse” at the bottom of the menu you will discover you can access profiles that have been designed by your specific camera manufacture for your camera. Again each one of these will alter the way in which Lightroom is representing the colours.
Profiles are akin to choosing different film types for an analog camera, in other words, you are introducing a certain colour world onto your image before you begin the rendering process. I find this influences how I process the image and I am guessing a different profile might well lead to a different outcome. If the profile I choose has an emphasis on certain colours while subduing others, this emphasis may lead me in a more limited direction. Starting with accurate colours I believe opens up more rendering possibilities for an image.
Start in something relatively neutral like Adobe Standard then would meet this need, but it is also possible to create a colour profile based on the camera you are using by using X-rite colour correction equipment. Using this process the company suggests your starting point should have a more accurate range of colours, providing you with a better starting point than Adobe’s generic setting. This, of course, is the source of much debate but in my experience starting with an accurate colour field has been helpful, just as getting the histogram balanced or the white balance correct. The X-rite system in addition to providing colour correction also provides me with a method of accurately calculating the white balance.
To illustrate the difference between these two starting points, Adobe Standard and X-rite I have processed the same image using these two profiles. The two versions of this image below are RAW images straight out of the camera (this is why they are rather flat in their look), the first image has the Adobe Standard profile applied to it and the second using my X-rite equipment.
You can see from the two RAW images that the differences are quite subtle, but in the first image, I see the greens are flatter and the sky is more monochromatic. Keep in mind depending on the quality of your computer screen, or how it has been calibrated, you may see different results, cheaper screens may show no difference.
The following images have been rendered or processed in Lightroom applying a series of adjustments with a somewhat heavy-handed treatment to colour saturation, to bring out clearly the differences in the different profiles. In the first image I applied the X-rite profile for my camera. The second image is identical to the first except I changed the profile to Adobe Standard. In theory, both of these profiles should have an accurate colour spectrum as both these profiles are designed for colour accuracy.
Even though the processing or my use of sliders in Lightroom was exactingly the same in both images the images are dramatically different, this can be seen in the colours in the sky and the colours in the grass.
I am not clear on why the results of the X-rite system are different, but in terms of the outcome, but to my mind they are cleaner and richer in colour. This is an esthetic observation and certainly, others may draw a different conclusion.