I've done a couple of workshops where we've done gradations of one colour, colour families and colour'n'complement. We dyed calico/muslin fqs in ziplocs and each of us took home at least 3 trays (I used cat litter trays) packed with plastic bags. The following day was rinsing day -and it did take all day and gallons of water. My hands and shoulders complained for ages afterwards. The workshops are great fun, and lovely though the fabric turns out to be, I'm certainly not up to doing it again. Besides we're on a water meter now!