Can't see speedometer at night
 

Hello, can someone help me figure out what I am missing, if anything? When it is dark out, and I move the instrument panel dimmer on my 2004 s40, only the red needles seem to be getting brighter. I can't see the numbers on the speedometer. Is there another bulb that is supposed to shine on them? I just purchased this car from a private party. I changed the lights that shine on the license plate, but those were obvious. I can't find anything about this subject in the manual, despite it being about 80 pages long. Even the list of bulbs doesn't help. Can you?

Thank you!!!