Bullsnakes are all considered a single species (or subspecies, depending upon whether you are a 'lumper' or a 'splitter'), but they are highly variable in regards to color, size, etc. They can also change coloration quite a bit as they grow and mature. Reds and oranges seem to take particularly long to develop, and sometimes solid blotches will fade, and stuff like that. It can be hard to predict sometimes, especially if you haven't seen the parents. Keeping all of that in mind, I would guess that yours will not have a bright yellow ground color, probably more of a tan to pale yellow, and some of the brown blotches may fade a bit. It reminds me of a fox snake in coloration. I think it will be a very nice adult with lots of contrast. Be sure to take pictures every so often so you can keep track of changes. Some don't change all that much, but some are quite amazing!