In the laundry red is the enemy. Ferris has some red t-shirts that bleed so much I won't put them in with anything but the darkest darks...and even then I wouldn't put in dark dress pants if they had light colored pockets - lest I want them pink.
To test color-fastness in the wash I use this nifty little method. The first time a new dark or brightly colored item goes into the wash, I toss in what I like to call an 'indicator'.
We use white bar towels around the kitchen...as mopeenes. After serving us well - when they get tattered or stained they get re purposed as dust rags.. and then eventually end up in the basement or garage for oil or paint clean-up sort of things. To tell the difference at a glance, my clever wife uses a sharpie to put dots on each corner. These then get sorted/folded/and stored in the laundry room rather than with the kitchen towels.
Anyhooo... I just toss one of these white dust rags into the load since I don't really care what color they are. If it comes out white, then I know I can safely wash the item without worry.