There are a few reasons why your contour might look too dark after blending. First, you might have applied too much product, making it difficult to blend in a way that looks natural. Secondly, it could be that your contour is simply too dark for your skin tone. Your contour should only be a couple of shades darker than your natural skin color. Thirdly, the issue could be that you simply haven’t blended thoroughly enough. Try blending a little more and see if this makes a difference.