The phrase "racial overtones" means that something has hints or suggestions of ideas, attitudes, or beliefs related to different races or racial groups. Full definition
Participants who were perfectly unbiased should have been able to pick the equivalent word pairs equally quickly, regardless of racial overtones. (scientificamerican.com)
That's not saying the author stays away from racial overtones. (nystateofpolitics.com)
And, in case anyone is concerned about weird racial overtones, the «china» bit refers to the fact that she's made out of porcelain. (io9.gizmodo.com)