That is precisely it. I'll admit that the hair lightness (couldn't care less if Lois has black, brown, red, or auburn hair - just wanted something darker as typically depicted in the comics) bugged me a bit before we got any spy photos or official shots of Amy as Lois on set. However, once we got the shots of Amy in suits and other office wear with her press badge, I stopped caring. It was the uniform of Lois's profession that defined her visually for me. Lois is her job.