During the production of the composites, the color of the granules alter depending on the process parameters used. For this reason, color measurement were carried out using the Ultra Scan Pro (Hunter Associates Laboratory Inc., Reston, USA). Color changes were examined using the CIE L*, a* and b* color space, in which L* represents the lightness from 0 (black) to 100 (white), a* expresses green/red and b* represents the yellow/blue dimension.