White for towels. I made that switch over the last few years, gradually replacing our towels with fresh new white ones from Restoration Hardware.
For our bed, we have two sets and alternate between white and tan sheets. Both go with the decor. The guest room alternates between eggplant and tan -- again, both go with the decor, and I just can't get rid of the eggplant ones. They are bamboo and SO SOFT.
I have fun color and prints -- some are, um, vintage -- for our inflatable beds that we use when we have lots of houseguests, especially since those tend to get used by kids. And some solid colors (sage green, blue) for the two futons in our house that also get used when we have lots of guests. The colors help identify what fits on what.