Whenever I wash my new fabrics I put a sheet of SHOUT color catcher in. Works Great. I've even put pastels with darks-never had a problem. It's in the detergent isle of the grocery store.
:!: If you really love your work and do not want to take it apart; buy a set of fabric paint (not the puffy kind). Play around mixing the colors until you get the desired color, test on fabric scrap. If you like it use a small tipped artist brush and patiently paint your pieces that got ruined. A pain staking project, a lot more work, but in the end the satisfaction is wonderful.
It's like having a baby, you never experienced pain like that before, but after the baby comes-you've forgotten all about it :P