Colloidal stability as well as physicochemical and rheological properties are among the critical determinants of the sensory quality of beverages. The present study investigated the effects of lecithin, xanthan gum, propylene glycol alginate, and their combinations on the colloidal stability and physicochemical/rheological properties of a model peanut-based beverage. A simplex centroid mixture design was applied, and the visual stability, centrifuge stability, physicochemical properties (soluble solids, pH, water activity, color), and rheological parameters (flow behavior and viscosity) of the samples were determined. All the evaluated parameters were significantly affected (p < 0.05) by the type and quantity of emulsifier or stabilizer used. At the 0.5% total usage level, the optimum stabilizer and emulsifier combination was that of 66% xanthan gum and 34% lecithin. A further increase of lecithin in the mixture caused a decrease in the colloidal stability of the sample. Irrespective of emulsifier and stabilizer type and quantity, all samples exhibited shear-thinning flow behavior, with samples containing xanthan gum being more pseudoplastic than the others. The prediction model for the visual stability index found in this study may be used by the industry to formulate similar beverages for better colloidal stability.