They have a house salad dressing at just about every Italian restaurant I have been to. Anyone know what it is

It is red in color. I has a tangy taste but a hint of sweet. Some of the Italian restaurants call it their house Italian Vinaigrette and some call it Red Vinaigrette. Does any one have a good recipe for something similar? I have always eaten Ranch dressing and not a fan of any other but I really do like this dressing.