Change categories background

Hello,

I would like to change the background image for all the categories inside the Blog section. I have a background image for the Blog main page, but this background is grey inside every category page.

https://www.estherssm-psicologia.com/mis-articulos/ <—- Background image OK

https://www.estherssm-psicologia.com/relaciones-interpersonales/ <—– Background grey

Thanks in advance!

The page I need help with: [log in to see the link]