Tiles in Portugal

I got this postcard from my flatmate, Kahti. Obviously, she knows that I am interested in interior and architecture, therefore her postcard from Portugal is my-hobby-related. From what she wrote to me on the postcard, ' you can find this kind of tiles everywhere on the walls of the houses in Portugal... it is blue and yellow - for Sweden '. I have never traveled to Portugal, so it is good to know it, thank you Kahti.