Adjectives

(s)dulled, benumbedhaving lost or been caused to lose interest because of overexposure“the mind of the audience is becoming dulled”, “the benumbed intellectual faculties can no longer respond”
(s)blunted, dulledmade dull or blunt
(s)dulled, greyeddeprived of color“colors dulled by too much sun”, “greyed with the dust of the road”