Two things helped with this problem for me. The first was to replace the dash bulbs, as they had deposited specs of filament on the inside of the bulb glass over the years. The second was to buy new indicator symbol strips for my w124 ($5 each side). The strips have the Hi beam, check engine, ABS, etc symbols printed on them, and get dusty and fade over the years. They slide out of the instrument cluster once it is removed, and the new ones slide in to the slots.
The Hi beam was a faded white color, and is once again deep blue and less obnoxious at night. The other symbols are also more visible.
2003 Firemist Red/grey leather SL 500
2015 Palladium Silver/black mbtex GLK 350
1987 Smoke Silver/burgundy mbtex 300E Sportline (SOLD)
Click to see 87 300E