With all things being equal, if you compare a colonial with a split level with the same condition, specs and location, the split will sell for less money.
Obviously, there is something that attracted you to this split and that should be the case when you go to sell it. It may be the condition and some of the features are better then similar homes in that price point.
You shouldn't pay more for a house than it is worth to you. However, just because it isn't worth it to you, does not mean that it wouldn't be worth it to someone else.
That all said, it is of some value to ascertain whether the split level is a common style in the neighborhood in which you are looking, there are pros and cons to being a unique style or a popular style in the neighborhood.
Hope that helps you.