One of the first questions most Jewelers get asked is - what kind of Diamond should I Buy? This question is not limited to just an engagement ring, it is pertinent to any diamond Jewelry you purchase.
So, how important is Color? Is Clarity more important than Color (after all, isn't the internals of the diamond the most important attribute that adds value to it)? Is it ok to compromise Size over Clarity? What about Brilliance?
A Jeweler's response will depend on many factors. Some that are evident, many that are not. Like the Dimensions, the presence of Fluorescence, the types of Inclusions, etc. Or it may depend on the inventory they have on hand, and how much you are willing to spend. That's the cold hard truth.
In general, we recommend a high Color, Larger Size, Brilliance and Mid to low Clarity (but not lower than SI). In larger stones, some Fluorescence is ok, probably good, because it improves the Color by offsetting the yellow, but lowers the cost. This balance will get you more bang for the buck and you will enjoy looking at your own stone than your neighbors :)!