Oh dear! I know this is an extreme example of bringing in different colours but it shows how it brake up that 'boxy' look. It's really common now to use two colours or more for units. You can be far more subtle using crisp whites, creams and shades of beige giving a more monochromatic look and feeling far more peaceful.
Oooooo...... I like this, grey is so underrated, it looks so crisp!
Q