International Journal of Current Engineering and Technology E-ISSN 2277 – 4106, P-ISSN 2347 – 5161 ©2015INPRESSCO ® , All Rights Reserved Available at http://inpressco.com/category/ijcet Research Article 651| International Journal of Current Engineering and Technology, Vol.5, No.2 (April 2015) CIELAB Color Spaces of Reactive Dyed Cotton Fabric Predisposed by Correlated Color Temperature of Illuminant and Depth of Shade Salima Sultana Shimo †* † Department of Textile Engineering, Daffodil International University, Mirpur Road, Dhanmondi, Dhaka-1207, Bangladesh Accepted 02 March 2015, Available online 13 March 2015, Vol.5, No.2 (April 2015) Abstract Color has a semantic content which touching directly our sentimental world. It has a significant influence on the aesthetic properties of textiles. Color is the result of dyeing a textile material depends on the chemical structure of the dyes and the physical and chemical properties. Manufacturers are expected to provide their material with a high level of quality in color so that it meets the needs of its customers. Role of illuminant and depth of shade on CIELAB color spaces were evaluated by Datacolor 650 (reflectance spectrophotometer) to get the difference in color spaces (DL*, Da*, Db*, DC* and DH*) of reactive dyed fabric focused on this paper. The color spaces of dyed fabrics shows higher lightness at higher concentration usually expressed by DL*. Correlated color temperature of illuminant is maximum for D65 (6500K). Fabrics became darker when the colorant concentrations increased as well as illuminants CCT. Samples showed evidence of more redness and yellowness than the standard. Saturation level of dye also influenced positively in most cases i.e more intensive in higher dye concentration and fabric GSM. Keywords: Correlated color temperature, Color spaces, Color Build-up, Illuminant, Shade depth, Reactive dye. 1. Introduction 1 Fibre Reactive dyes,class of highly colored organic substances which attach themselves to the substrates by a strong chemical reaction by forming a covalent bond between the molecule of dye and that of the fibre. The dyestuff thus becomes an integral part of the fibre and is difficult to be removed by washing that adhere by adsorption. Mainly cellulosic fibre dyeing with reactive dye significantly improves the product's color stability and wash ability. Thus reactive dying of cotton is currently the most pervasive dying process in the textile world. Dye-fibre bond formation is encouraged by alkali. Reactive dyes are anionic in nature and cellulose also contains hydroxyl group, salt used in dye bath, works as electrolyte to neutral the fibre surface and encourage dye exhaustion. During dyeing, under alkaline condition the reaction takes place between the reactive group of such dye and water instead of reaction with fibre, which results on the loss of dyes. This phenomenon is known as dye hydrolysis. The rate of this hydrolysis becomes greater when temperature increases. The effluent load becomes greater due to hydrolysis (A D Broadbent, 2001; Dr. V. A. Shenai, 1993). Color can describe precisely by measuring the intensity of visible electro-magnetic radiation at many distinct wavelengths namely spectral power *Corresponding author: Salima Sultana Shimo distribution (SPD).Visual perception of color mainly dependent on the spectral composition of observed radiant energy. Color practiced as a characteristic of a surface. The three key properties of a surface color are Hue, Saturation and lightness. Hue permits a certain color to identify of an object as red, blue, yellow, green and so on. Hue mainly distinguishes one surface color from another. Saturation is termed as strength of Hue or intensity of a color i.e vividness or dullness of color, it’s another name is Chroma. Lightness describes luminous intensity of color i.e. black (total absorption) or white (total reflection) (Deane B. Judd,1940). CIELAB is the most complete color space defined by the International Commission on Illumination which describes all the colors visible to the human eye and was shaped to provide as a device- independent model to be used as a reference. The color coordinates were measured by using CIE LAB due to having its widespread use. The CIELAB scale generally gives better approximation to visual evaluation of color difference for very dark colors and expands the yellow region of color in comparison with Hunter L, a, b scale. Both scales are mainly based on opponent color theory (Application note,2001;V.K.Sikri,2010). The three coordinates of CIELAB represent the lightness of the color (L* = 0 yields black and L* = 100 indicates diffuse white, a*, negative values indicate green while positive values indicate red and b*, negative values indicate blue and positive values indicate yellow. The asterisk (*) after L, a andb are