To photograph color well, I think one must be acutely aware of color. By that I mean you must not just notice colorful things, but analyze the relationships of colors to each other within a composition, and understand how the color temperature, quality, and direction of light either accentuates or mutes these colors. The color of objects is an actual part of the finished package.
To photograph black and white well, I think one must be acutely aware of tonality and tonal relationships. This requires an understanding of how colors will translate to a grayscale, and relies more on the interpretation of things such as form, shape, motion, and texture to create an emotional impact, as color is no longer part of the equation.
One's choice between color or black and white is largely dependent upon what you wish notice when out photographing, or what photographers often refer to as how you wish to "see". I think if colors are of primary impact and enjoyment then one should work in color. If the beauty of tonal relationships is more important, then black and white.