Would mixed grains or black rice be better for dieting?

I always eat only white rice.

I've reduced my portion size a bit lately because I'm on a diet.

But now that I think about it, since I'm going to eat anyway, wouldn't it be a bit more helpful for my diet if I ate mixed grains?

Or would black rice be okay?

Since black rice is black, it is also more nutritious.

Since the chewing texture is similar to white rice compared to mixed grains, would it be too heavy?