Texture analysis such as segmentation and classification plays a vital role in computer vision and pattern recognition and is widely applied to many areas such as industrial automation, bio-medical image processing and remote sensing. In this paper, we first extend the well-known Gabor filters to color images using a specific form of hypercomplex numbers known as quaternions. These filters are constructed as windowed basis functions of the quaternion Fourier transform also known as hypercomplex Fourier transform. Based on this extension this paper presents the use of these new quaternionic Gabor filters in colour texture image segmentation. Experimental results on two colour texture images are presented. We tested the robustness of this technique for segmentation by adding Gaussian noise to the texture images. Experimental results indicate that the proposed method gives better segmentation results even in the presence of strongest noise.