An electrochromic device comprising: a first substantially transparent substrate; second substantially transparent substrate substantially parallel to the first substantially transparent substrate and spaced apart therefrom; and an electrochromic medium disposed between the first substantially transparent substrate and the second substantially transparent substrate; wherein: the electrochromic device is configured to exhibit a contrast ratio of at least 2,000:1, a darkening time less than about 30 seconds, and a clearing time of less than about 150 seconds; and the electrochromic medium comprises an anodic electroactive material comprising a phenazine and a cathodic electroactive material comprising N,N'-dialkyldipyridinium compound, wherein the cathodic electroactive material is present in the medium at a concentration of at least 50 mM, wherein the clearing time refers to the time required at short circuit for an electrochromic device, starting in a minimum low transmission state and after maintaining the device in the minimum low transmission state for at least 250 seconds, to attain 98% of the transmission range between the minimum transmission value and the maximum transmission value of the device as measured at short circuit, the darkening time refers to the time required for an electrochromic device to transition from a high transmission state at short circuit (or in an unpowered state) to reach 90% of the transmission range between the highest transmission value and of the lowest transmission value of the device, and wherein the anodic electroactive material comprises a 2,7-dialkyl-5,10-dialkyl-5,10-dihydrophenazine compound, and at least one alkyl of the 5,10-dialkyl groups has at least four carbon atoms, and is void of any β hydrogen atoms; and at least one alkyl group of the 2,7-dialkyl comprises at least four carbon atoms. a first substantially transparent substrate; second substantially transparent substrate substantially parallel to the first substantially transparent substrate and spaced apart therefrom; and an electrochromic medium disposed between the first substantially transparent substrate and the second substantially transparent substrate; wherein: the electrochromic device is configured to exhibit a contrast ratio of at least 2,000:1, a darkening time less than about 30 seconds, and a clearing time of less than about 150 seconds; and the electrochromic medium comprises an anodic electroactive material comprising a phenazine and a cathodic electroactive material comprising N,N'-dialkyldipyridinium compound, wherein the cathodic electroactive material is present in the medium at a concentration of at least 50 mM, the electrochromic device is configured to exhibit a contrast ratio of at least 2,000:1, a darkening time less than about 30 seconds, and a clearing time of less than about 150 seconds; and the electrochromic medium comprises an anodic electroactive material comprising a phenazine and a cathodic electroactive material comprising N,N'-dialkyldipyridinium compound, wherein the cathodic electroactive material is present in the medium at a concentration of at least 50 mM, wherein the clearing time refers to the time required at short circuit for an electrochromic device, starting in a minimum low transmission state and after maintaining the device in the minimum low transmission state for at least 250 seconds, to attain 98% of the transmission range between the minimum transmission value and the maximum transmission value of the device as measured at short circuit, the darkening time refers to the time required for an electrochromic device to transition from a high transmission state at short circuit (or in an unpowered state) to reach 90% of the transmission range between the highest transmission value and of the lowest transmission value of the device, and wherein the anodic electroactive material comprises a 2,7-dialkyl-5,10-dialkyl-5,10-dihydrophenazine compound, and at least one alkyl of the 5,10-dialkyl groups has at least four carbon atoms, and is void of any β hydrogen atoms; and at least one alkyl group of the 2,7-dialkyl comprises at least four carbon atoms.