I always consider color in user experience design as an aspect of balance and hierarchy, and once you take away the focus on color you can better see the visual weight of each component of color.
Color can mean different things both contextually and culturally but grey scale can help you better determine visual weight and order. This is also important to consider with regard to accessibility. A user who is color blind might not see the color you intended but they will most likely get a sense of meaning and intent from visual relationships. That’s why wireframes are generally shown without the use of color so the focus stays on the layout and organization of content. A key element of good design is to use color in the service of supporting content.