while I don't think color is meaningless, it is still a very poor indicator of the oil's health, especially if the engine runs well and there aren't any other problems. If your engine is well-maintained and you start having issues with the engine AND the oil becomes darker quicker, that color change then has meaning. I've seen poor-running, worn-out engines turn new oil as black as oil in an old diesel! That's not to say that that made my grandpa wanna maintain his old Blazer any better, but, in this case, the oil's color did mean something (e.g., more blow-by that was likely caused by poor maintenance, which started a vicious cycle.)