I would wash in Synthrapol. If you want to make absolutely sure, after pre-washing everything, I would cut a piece from each fabric and either sew them together or safety pin them together and wash again. This will show you if the white picks up any color from the other fabrics. Some whites will not pick up color; other whites will. It's not only about how much the colors bleed; it's also about how much loose color the light fabrics will pick up.