Thank you, ladies and gentlemen for your prompt responses.
I did notice colours, however, when I checked they did not make much sense, on my own hubs I would be "coloured" yellow (sort of) as a Level 7 commenter, and two other hubbers who were guests would be "coloured" as hub authours.
Now - 77 min later when I checked - it has already changed - now I am a "recognized" author on my hubs and guests are commenters with different ranks.
Colours have disappeared. (I liked colours, it broke the monotonous flow and and broke the block-structure of it). The colour also helps the eye to quickly recognize the transition of speech from one person to another. We are very visual and I am doubly so. I always make my hubs illustrated. if you don't like my content, chances are you will still enjoy the presentation (browsing through pictures without reading). This is not an advertisement.
The peculiar thing has happened with this question, though. I had no notifications that it was answered. I came to check and the first place I checked was my e-mail, then I went straight to look at "Your questions" section only to discover that it was indeed answered and only then I wanted to say that the colouring scheme did not work and I checked my hubs again and it was changed.
Sometimes things are just strange.
Thank you all!