This paper focuses on the assessment of colour properties of reactive dyed cotton fabrics at four different shades under the illuminants of D65, A and F11 by using CIELAB and Hunter systems in computing. The fabric samples were dyed with four reactive dyes (black, yellow, red and navy) at ten different dyeing concentraiions (% owl) and the colour coordinates of the dyed samples were measured by a reflectance spectrophotometer. Colour coordinates and colour differences of the resultant dyeings were calculated according to CIELAB and Hunter systems and the results were discussed in accordance with the shades obtained. The colour results which were calculated according to CIELAB and Hunter systems were found sensitive to the shade variations. Black, yellow, red, and navy shades were found sensitive to illuminant choice when the colour coordinates were calculated according to the Hunter system. The highest differences between the calculated colour coordinates were obtained at yellow shade.