Stock radio lights

Some of the lights on my stock radio do not work. Light the number 1,2,3,4, buttons for the radio stations. The other lights work. Are these LED's? Or is there a set of bulbs in the background somewhere I can replace?

FYI, 97 Malibu. Stock AM/FM cassette player.

Thanks!

I've taken the radio out before and I don't think that there are any servicable parts inside the radio...almost positive their LED's