Are you thinking of re-upholstery the couches? I would go with a fabric that has a pattern since you already have a plain sofa in the adjacent area.

Could you do without the single chair (the one with pillows)? If not, I would re-ulphoster it in a complementary fabric.

Salon as in living room? I think there are too many patterns and the room is divided where it could be grand. Can you add a picture of the solid couch and other walls? The large art piece doesn't need to go behind the TV.

There is a lot going on in this space. You should get rid of the old sofas, move the couch against the freestanding wall, and add a lounge chair. The brown sofa is fine, but the paint colors and art should be updated a bit.

Jin are you happy? do you need more ideas?

Thank you all this is was really helpful.
I want to share with you what a friend suggested as a choice for furniture but with a change of the colors on upholstery.
The bench will go under the mosaics, and the console to support the back of the sofa (purple one in front of the tv) 1 seater sofa infront of the window. Give me your feedback please. Thank you a lot.