The tilted gel phase of lipid bilayers can display in-plane orientational texture due to long-range alignment of the molecular director. We explore systematic variations of texture defects in a series of binary phospholipid membranes. Using polarized two-photon fluorescence microscopy, the texture pattern of single domains is revealed. The appearance of a central vortex-type defect in each domain correlates with a particular range of hydrophobic mismatch values h > 1 nm at the domain border while domains with h approximate to 1 nm correlate with uniformly aligned texture. The central vortex defect is characterized by a defect angle, indicating its bend or splay nature. Using image analysis, we measure the defect angle and find that it has primarily bend character for small mismatch values (h approximate to 1 nm) and primarily splay nature for larger values of h. For domains containing a vortex, the domain shape is decoupled from the texture while for uniformly textured domains there is a preferred texture orientation of similar or equal to 45 degrees along the domain border. The results establish a foundation for understanding texture phenomena in compositionally complex membranes.