When I started hiking I made the conscience decision to avoid gear that was red. The idea was that if I were bleeding I wanted to know and for it to standout. Then about 6 months ago I decided that black was an interesting color because it would dry my gear more quickly. That included my poncho and at the expense of being seen.
Last week I purchased a "Black Pearl" kit from Light My Fire. It's a Morakniv knife with included fero rod, a spork, and tinder; all black. Soon after I placed the purchase I found an orange spork in my kit that was dirty. At that moment I realized a black spork was a bad choice. If the kit was dirty it was going to transfer. Yuk!