Women might have changes in perception and cognition of colours according to hormonal changes during the menstrual cycle. Colours are often associated with specific emotional facial expressions, but how these two factors interact with each other and differ according to the cycle has remained unclear. We investigated attentional interference between colours and emotional facial expressions for women in the menstrual compared to the ovulation phases by colour judgment based on the Stroop tasks. Participants identified the colours (either red, yellow, or blue) of three types of face stimuli (happy, neutral, or sad) and corresponding scrambled face stimuli by pressing buttons, and we recorded participants' reaction times. The results showed better performance in the menstrual phase than in the ovulation phase. An interference effect was not observed. However, in the scrambled face stimuli task, only the reaction time for happy scrambled face shape and red did not differ between the phases. Thus, participants might pay stronger attention to faces with colours in the menstrual phase than in the ovulation phase but weaker attention to scrambled face shapes in the menstrual phase.