The text of the continue reading is the wrapper link color, you can change it there.
The background of the continue reading can be change with the CSS rule below placed in the Theme Global custom CSS rule box
.more-msg {background: #C12311;}
There may be a theme setting for it, but I can’t recall….
For the images, I would doubt it would resolve itself. If it does not, you may need to copy the folder structure with all the images in the right location so the path becomes valid.