Colour influence subject is popular term used in many pop-psychology articles and it suppose impact on our minds is used to advantage of artists, advertisers and other groups of influence with some degree of questionable success. Regardless there is relatively little published study exploring factors behind perception of colour in context of its universal influence on human psychology. The aim of our study was to analyse if there is a particular tendency in choice of images colour brightness by a cohort of healthy adult professionals in a light of their actual “overall emotional state” (mood, stress level, positive and negative effects) controlled for fatigue. Sixty-eight, healthy and working in office professionals (34 male, 34 female) participated in the experiment. Divided equally in two groups: tired n=34 and rested n=34. Multivariate analysis of variance was used to study the difference affects between colour brightness on fatigue and overall emotional state. Two-way analysis of variance was used study the separate effects of stress, positive/negative effect and stress in (tired/rested) conditions on preference of colour brightness. Our only significant results suggest shows influence of negative effect and stress on choice of colour brightness. This suggests that its rather strong negative emotions rather overall mood that effects cognition and perception of colour.