The display polarity effect refers to the finding that positive polarity (dark contents on a light background) generally allows for more accurate and faster reading of text and faster recognition of stimuli than negative polarity (light on dark). While many polarity studies have used traditional two-dimensional monitors for stimulus presentation, there is less research on polarity in virtual and mixed reality, particularly in relation to video see-through headsets. Therefore, these two datasets contain the data from two experiments on polarity in virtual reality (Study 1) and video see-through mixed reality (Study 2).