variables

Is there any way to use variables within CSS? For example: I am creating a style sheet which includes various colors (background colors, font colors, etc). Every time I experiment with different colors, I have to do a scan/replace to change all the references to a given color. This becomes...

In theory, that might be possible. Except... do you think science can ever control for the variable time? This is slightly (philsophically) problematic since even exact repetitions would not be the same on all variables, since time would be different.