Satins can be of any color.
ian is correct: on a good black there's very little difference between satin and non-satin (the more pigment you have, the less noticeable it is). In fact, you often have to check for any tan-hairs to be able to tell! The effect is not same on blue, though blue satins tend to be a bit darker in color than non-satins, which is an effect of the satin on any color. This is why some varieties benefit from satin while others look better without it.