So slight as to be difficult to notice or appreciate
Able to make or detect effects of great subtlety or precision
It was a subtle shade of gray.
Xander saw the subtle signal Damian gave his brother.
Everything in the room radiated some sort of subtle energy, and she waded through the energies, marveling and confused by them.
There were subtle differences between the parties regarding living wills.
The dish was subtle in flavor.