Check out http://www.worldofballpythons.com/morphs/lesser/
and http://www.worldofballpythons.com/morphs/butter/
There are good examples of the morphs on that site, pictures would vary from size/age of snake(hatchlings look different), the photo quality itself, and the bloodlines for the particular snake.
Very similar looking morphs but from different blood lines. Personally I cant tell the difference, if it was sold to you as a butter than chances are, it is.
Congrats on your new addition though!![]()