Even though red onions look so different from other onions, they are comparable to yellow onions in flavor, their layers are somewhat less meaty and tender. They lean more towards the sour-end of the taste spectrum. Red onions are most often used in salsas, salads, and other raw preparations for their lovely color and mild flavor.
Tip: if you discover the flavor of red onions too astringent for eating raw, try soaking them in water before serving.
For cooking and other resources see Onion Recipes and information