If you want to get rid of the red vertical lines:
1.Open the ItemHorizontal layout
2. Select Transparent for the dropdown list for the 'Divider color' property. See image
View attachment 139200
And if you want to get rid of the gray border around each image:
1. Open h_Item layout
2. Select Panel1 properies
3. Make the changes to color, corner radius, border color, border width. See the 2nd image:
View attachment 139202
You will end up like the 3rd screenshot:
View attachment 139203