1999 Audi A6 brake light in my digital display
 

I have a yellow brake light indicator on in my digital display but I can barely see anything due to it fading away. My car beeps and the light comes on in the display but I can't see it. When it's cold I can tell it says brake light in the yellow top part. My lights all work fine too so I don't what's the problem can be. Any help would be appreciated thanks