Unfortunately, as most people learn doing things for the first time, not everything goes the way you'd like it to. In this case, I learned that body filler develops pinholes while curing, and this is pretty much impossible to prevent. This was not hardly noticeable through the primer, but as soon as color was added, the problem became very apparent. Thankfully, there's a very easy solution to fix the pinholes by using some glazing putty since this compound fills very fine imperfections. (If you look closely at the pictures below after more sanding was finished, you can see the little red dots that used to be the pinholes; the large red splotches are low spots from the body filler.)