The living area, kitchen and dining room are open, I would paint all the walls the same color but perhaps paint an accent wall or two a complementary color. You can't go wrong with white or a light neutral for the main paint color.

BM Revere Pewter is a versatile neutral color and would work well for all the walls. Despite being in the gray family, it plays well with warm colors. No need to paint everything the same. It's hard to tell what might benefit from a different color without seeing the rooms. No more the 2 colors total.