The Italian term "appannato, insipido" matches the English term "dull"

other italian words that include "appannato" : english :
semibuio, torbida, appannato dim
appannato matt
other italian words that include "insipido" : english :
insipido charmless
insipido flavorless
insipido flavourless
insipido tastelessly
insipido unmagical