I think the bump-stop that slips over the top of the strut shaft is the color you noted - probably not a worry at all. The harshness could be worn-out struts, bad strut mounts, wide rims, low-profile tires, worn tires, too much air pressure.

Another issue to consider is - is the 'bump' response really harshly felt, or do you just hear a noise that fools your mind into thinking it 'feels' harsh? Try the same bump with a wool cap over your ears, or the music up loud, etc.

Steve