Thanks so much for your answer.
Indeed, there was a lot of formatting that I didn't see. Now that is in plain text works :)
I cannot see any attachment so I didn't manage to try yours but now it works. The only thing is that my "negative values" are now displayed in pink with blue borders rather than all blue..To change this should I flip the red or blue column too?

In any case, thank you so much for your help and time.