Qupid pastel platform sneakers

I first bought the size 7 brand new online and only wore them for a few hours. I am normally a size 7.5/ Eu38 and These 7s say EU38 but they were too small so I then ordered the size 8. The size 7 has yellowing inside the left shoe (pic #5) that was like that when I received them. It dont make since either because clearly the bottoms were white and never walked on. After the first pic of both sizes the next 4 pics are the size 7 and last 4 of the size 8. I did wear the 8s a handful of times, see bottoms.