As @Vortico notes, if it has precedence in the cascade, it may be to override an earlier background color assignment. Also, the W3C validator issues a warning on elements where the color is explicitly stated but the background is not. This isn’t really an error. It is just telling you that safest practice is to explicitly state both color and background where one is stated. Transparent is the default, so doesn’t really need to be stated unless overriding some assignment further up the cascade, but stating it anyway gets rid of lots of warnings in the validation report, and thus makes zeroing in on real problems far easier. I always state it for just that reason.