Not all racial slurs are equal in everyone's eyes. What some people consider racial slurs, others say out of ignorance (less common, in today's sensitive reaction to them).
Consider "colored" compared to "nigger". Colored will definitely be seen by some as a racial slur, but to others it may be the appropriate for the time, not necessarily racially charged, correct terminology they initially learned. For that matter, "nigger" was a fairly neutral term originally, but changed over time, as the circumstances of the people it referred to changed and they preferred a different, less loaded moniker.
Consider "colored" compared to "nigger". Colored will definitely be seen by some as a racial slur, but to others it may be the appropriate for the time, not necessarily racially charged, correct terminology they initially learned. For that matter, "nigger" was a fairly neutral term originally, but changed over time, as the circumstances of the people it referred to changed and they preferred a different, less loaded moniker.