Based on the Preface, Introduction, and Chapters 1-4 of Ian Haney López's "Dog Whistle Politics: How Coded Racial Appeals Have Reinvented Racism and Wrecked the Middle Class," why is "color blindness" the dominant behavior when discussing race today?

When discussing race today, colorblindness seems to exemplify the dominant etiquette or accepted behavior. This stems from the fact that colorblindness has a strong moral appeal. It envisions a world where race ceases to be a point of contention and where everyone is perceived to be equal.
It also has a practical appeal in the sense that it is seen to encourage equality through the process of limiting discussions about race. Additionally, colorblindness appeals to white Americans who fear the minefield of race discussions. Thus, avoiding debates on race allows white Americans to feel more confident about how they are perceived by minorities. As a rule, most white Americans do not want to come across as bigoted or ignorant. So, adopting a colorblind approach is both personally empowering and satisfying to sincere whites.
However, Lopez maintains that colorblindness actually promotes what he calls dog-whistle politics, where a subgroup of the population interprets the notion differently from other groups. He argues that racism cannot be dealt with effectively when "constant racial insinuations" are allowed to go unchallenged. In his book, Lopez aims to show why the underlying connotations behind the notion of colorblindness must be addressed before true equality can be accomplished.