I have a shapefile of polylines for trails, and I need to convert them all to be polygons that are 8 ft wide (4 ft from the center of each side of the polyline). I tried a following a few other posts that I thought were doing the same thing, but I always just ended up a big blob of color.
I can't tell if "blob of color" means all the trails are now joined together, or that it takes a lot of screen area.
If the former, see if you have
dissolve buffer results checked, as it will dissolve all the 8 ft wide polygons representing individual trails into one.
If the latter, it might be a symbology problem, where you have set the outline too thick, try thinning it, or changing the border of the polygons from millimeters to map units.