The objective of this research was to assess the effects of three different colours on the interior wall surfaces of classrooms on the perceptual performance of male students, taking into account of their class distinctions. A semantic differential scale composed of 11 bipolar adjectives was applied in order for students of the Incirli Vocational High School, Ankara, Turkey, to evaluate photographs of classrooms with cream, blue and pink wall surfaces. According to the results, spaces with blue walls were perceived to be more positively compared to cream or pink coloured spaces. In addition, it was determined that 9th grade students perceived the spaces more positively compared to 10th, 11th and 12th grade students at level p<0.05. The results of the study clearly indicate that the use of different colours in interior spaces of a classroom has a statistically significant effect on the perceptual performance of the male students.