A computer-implemented method, comprising: receiving , by a computing system, a video showing a scene from a field of view of a video camera (230; 330); detecting , by the computing system and based on analysis of the video, an object (110; 118) that appears in the scene of the video; identifying , by the computing system, a visual marking (112; 114) that appears on the detected object; determining , by the computing system, a particular pre-defined visual marking, among a plurality of pre-defined visual markings available to the computing system, that matches the identified visual marking, wherein at least some of the pre-defined visual markings, including the particular pre-defined visual marking, identify one or more object characteristics that include a colorization of the pre-defined visual marking or a colorization of the object; identifying , based on stored data that correlates the plurality of pre-defined visual markings with characteristics of respective objects on which the pre-defined visual markings can appear, one or more object characteristics associated with the particular pre-defined visual marking including a colorization that matches the colorization of the identified visual marking in the video, or the colorization of the detected object in the video; evaluating one or more features of the video by comparing the colorization of the identified visual marking in the video to the colorization of the pre-defined visual marking included in the identified one or more object characteristics, or by comparing the colorization of the detected object in the video to the colorization of the object included in the identified one or more object characteristics; and based on a result of evaluating the one or more features of the video, calibrating the video camera by adjusting a colour setting of the video camera. receiving , by a computing system, a video showing a scene from a field of view of a video camera (230; 330); detecting , by the computing system and based on analysis of the video, an object (110; 118) that appears in the scene of the video; identifying , by the computing system, a visual marking (112; 114) that appears on the detected object; determining , by the computing system, a particular pre-defined visual marking, among a plurality of pre-defined visual markings available to the computing system, that matches the identified visual marking, wherein at least some of the pre-defined visual markings, including the particular pre-defined visual marking, identify one or more object characteristics that include a colorization of the pre-defined visual marking or a colorization of the object; identifying , based on stored data that correlates the plurality of pre-defined visual markings with characteristics of respective objects on which the pre-defined visual markings can appear, one or more object characteristics associated with the particular pre-defined visual marking including a colorization that matches the colorization of the identified visual marking in the video, or the colorization of the detected object in the video; evaluating one or more features of the video by comparing the colorization of the identified visual marking in the video to the colorization of the pre-defined visual marking included in the identified one or more object characteristics, or by comparing the colorization of the detected object in the video to the colorization of the object included in the identified one or more object characteristics; and based on a result of evaluating the one or more features of the video, calibrating the video camera by adjusting a colour setting of the video camera. <EOS>