I would say smoky black isn't always smoky, but very often is - to me it just looks a little bit different from a completely black, just a bit washed off looking - and yes some are 'on the border' and really look like other colors. But most of the time, the smoky black - to me, honestly, yes, it just looks somewhat 'smoky'. Not like a cream or Weimereiner color, but just a bit 'washed off'. For me the real tip off it's a smoky black is that the mane and tail color is very close to the body color. We almost bought an Icelandic of that color.
And actually, it is extremely rare that a black does not fade in sun - new research in color has shown that.
There now is a genetic test to differentiate black and bay from brown, so if you really are interested in seeing what your horse's color is based on its genes, you can do that.
There are other ways to tell what genes an animal actually has for color, for example, test breedings.
Also just because a black looks "washed out" does not mean that it is carrying cream either. The only
way to know if a horse is a smokey black is to test (unless you want to take a chance with breeding, but why do that when a $25 test will tell you for sure?). You cannot
tell smokey black by looking. Same thing goes for smokey brown.
I would never
recommend test breedings just to figure out what color a horse is. Genetic testing is the cheapest and easiest route for that without adding to the horse population. Also test breeding is not possible if the horse is gelded or spayed.