Wig Color - It's All About the Lighting
Your hair (wig) color is never going to look exactly the same in every single light.
All hair reflects light. The hair color we see is actually light reflecting from its pigments. The Oxford Dictionary defines color as “the property possessed by an object of producing different sensations on the eye as a result of the way it reflects or emits light.”
Under blue or cold white lights, your hair will reflect a more "ash/cool" color. In warmer yellow-based lights, your hair will reflect a warmer, honey to brass color. Also, the lighter your hair, the more light reflection you get. The darker, the less light it reflects and the more shine you will get.
Therefore the best way to see what your hair color actually looks like is to go outside with a mirror in the natural sunlight. Also note that unlike sunlight, most light bulbs do not produce the full spectrum of color. As a result hair in artificial light can appear darker.