Preheat the oven to 400°. Wrap the beets in a double layer of aluminum foil and roast for about 1 hour, until tender. Let cool, then peel the beets. Thinly slice the red beets and cut the golden beets into wedges.
In a small bowl, whisk the balsamic and Champagne vinegars with the mustard. Whisk in the olive oil in a thin stream, then whisk in the marmalade and season with crushed red pepper, salt and black pepper. Transfer half of the dressing to a large bowl and add the mesclun, watercress and daikon. Toss well and transfer to plates. Add the beets and the remaining dressing to the bowl and toss to coat. Scatter the beets all around the greens and serve right away.