subtle
US /ˈsʌt̬.əl/
UK /ˈsʌt̬.əl/

1.
sutil, delicado, imperceptível
so delicate or precise as to be difficult to analyze or describe
:
•
The painting had a subtle blend of colors.
A pintura tinha uma mistura sutil de cores.
•
There was a subtle change in his expression.
Houve uma mudança sutil em sua expressão.
2.
astuto, perspicaz, discreto
making use of clever and indirect methods to achieve something
:
•
He used a subtle approach to persuade them.
Ele usou uma abordagem sutil para persuadi-los.
•
Her subtle hints were finally understood.
Suas dicas sutis foram finalmente compreendidas.