Did more changes to the CTS client and now getting closer to a final version, still in beta, still things to sort out, but getting there soon.
For a start, changed the layout:
Then added a graphic view that allows users “see” what is selected. Using left and right mouse click on the image can select or un-select the colour where the mouse points. Everything is in real-time and colour definition can be tested capturing another image with different lighting, resolution, etc: