Hi @VivMendes,
I am not entirely sure I understood what you want to achieve, but here is a simple way of achieving what I think your intended result is:
Plotting directly a matrix is anyway a shorter way to create 7 independent scatter traces.
Using map you can easily create those scatter assigning a custom name (or any other attribute for what matters).
If what you wanted to achieve is different, please let me know.
Edit: regarding using restyle!() inside Pluto, it is not entirely correct. You can’t restyle the output of one cell from another cell, but you can restyle a plot object before sending it as output to a cell (like inside a let block as I did above, I just think restyle is not the best approach if you just want to give custom names to traces).