Bring a medium pot of lightly salted water to a boil. Add the black-eyed peas and simmer until just tender, 30 to 35 minutes. Drain and rinse under cold water to cool.
Meanwhile, heat the olive oil in a small skillet over medium-high heat. Add the scallion whites, turmeric and coriander and cook, stirring, until the scallions are light golden, 2 to 3 minutes. Transfer to a large bowl and whisk in the vinegar, 1/2 teaspoon salt and pepper to taste.
When the peas are ready, add them to the bowl with the vinaigrette along with the radishes, bell peppers, scallion greens, cilantro and parsley. Season with salt and pepper to taste. Serve at room temperature or cold.