Why is the phrase, the color of water, the title of his book?

When James asks his mother whether God is black or white, he is a boy living in a predominantly black community with a mother who looks white, and is simply expressing his personal confusion about race. To add to the confusion, however, his mother simply responds that she is "light-skinned". When his mother explains that God doesn't have a color, and that God is "the color of water", the image converges questions of racial and religious division into an essence that is clear and universally spiritual - in other words, "human".