There are seven basic style essences. People can be pure essences, or they can be blends. If you count two-essence and three-essence blends, there are 63 possible types in the Truth is Beauty Style Identity System.
Most people find that three essences is the maximum needed to account for their beauty. It's rare for people to go beyond that, for two reasons.
One is that 4-plus essences is more visually complicated than most of us get.
The second is that, at a certain point, a combination of five or six or seven essences can start to look like a balanced average, which is itself an essence -- Classic.
But I do see a mix of four occasionally.
In those cases, a woman can usually view one of the four as an "accent" essence, to be sprinkled in with a more typical three-way blend, or as a "fudge factor" essence, to fill in any small aspect of an ensemble that isn't accounted for by one of her other three essences.
I myself have a dash of Romantic and a dash of Ingenue. Most of the time, I ignore them because they're so small. Occasionally, I bring in one or both if the options for the item I'm choosing aren't available in Ethereal or Natural. For example, if my only earring options are tiny and delicate, I can wear them, knowing that my tiny bit of Ingenue gives me room for that.
Not sure of your style identity? Try the Style Identity Calculator, or consider a virtual analysis.