I’m afraid the SnapLogic UI is rather misleading here. When you see “Base64 encoded data” for a field’s content in the preview output, it really means that the field contains binary data (an array of bytes). If it were really Base64 encoded data, you would just see a string containing the Base64 encoding of the binary data. I think this is because the UI is reflecting the representation of the preview data it’s getting from the control plane, rather than the actual raw data being passed between snaps.
So, the $CONTENT field from Oracle is the binary data itself – a byte array. How were you planning on hex-encoding that? I don’t believe that our expression language provides a hex encoding function similar to the Base64.encode() function it provides.