Brown and gray are both neutral colors, but brown is considered a warm neutral color, while gray is considered a cold neutral one.
Brown shades dominant in one's dream usually relate to the primitive instincts one holds within his/ her subconscious and to basic feelings, emotions etc. - because brown is the 'down-to-earth' color to be found all around in nature, in wood and earth.
Brown as dream image also stands for a feeling of stability, security and steadiness one experiences in the waking life. Brown is the color of wood, therefore symbolizes endurance, durability and fastness. Hues and tones of brown in a dream may be reflective of one's strength, power, ambition, perseverance and even stubbornness. Moreover, brown may also denote emotional balance and general life equilibrium, a state of happiness and wellbeing.
As brown is also the color of earth, in dreams it may stand as a metaphor for 'being down-to earth', for simplicity, practicality, raw energy, honesty, true friendship and good health. Consequently, the warm neutral color will depict a simple, practical, honest, upright, reliable and friendly nature which seeks for domestic and physical comfort in the waking life.
Brown may also be a symbol for fertility and procreation. From this point of view, when dominant in dreams, it may announce new beginnings and changes for the better to follow in one's life. Please note that fertility and procreation do not refer exclusively to having an offspring - it may be all about new ideas, decisions, undertakings, situations etc.