The invention relates to an electrochromic device having (a) a pair of glass or plastic plates or plastic films wherein at least one such plate or film is provided on one side each with an electrically conductive coating, wherein (1) at least one such plate or film and its conductive coating is transparent, (2) the other such plate or film and its conductive coating is optionally mirrored, (3) the electrically conductive layer of one or both of the two plates or films is optionally divided into separate segments optionally provided with individual contacts, and (4) the plates or films are joined on the sides of their conductive coating by means of a sealing ring to form a volume; and (b) the volume formed by the two plates or films and the sealing ring is filled with an electrochromic medium containing certain dihydronaphthazines or dihydrophenazines.