Its called color fade. The heat starts to bleach the color out of the injs after a while. This problem happens more on FWD SR20DETs with top mount intercoolers like the U12. If you see injs in this condition then you can also make an assumtion that they have alot of miles on them.gpriceynissan said:Has anyone else heard of or seen brown top 370's? I have one purple one that I bought new, the other three I bought used--supposedly 370's, but they have a brown color to them. I DID search, to no avail.