First, let's be perfectly clear about something. ESL (English as a Second Language) is not taught in China. EFL (English as a Foreign Language) is taught in China. The distinction is important for various reasons, but generally speaking they are very dissimilar.
Secondly, if you think foreign teachers are not tarnishing the image of the EFL system in China, you're walking around with blinders on. A huge percentage of "teachers," as has been noted in this forum in multiple posts, make very little effort to improve the quality of English education here, and instead blame everyone but themselves. As for racism, you'll have to elaborate on that before I can agree or disagree or even comment about it, as your meaning is far from clear. Does racism exist in terms of hiring practices? Decidedly so. But how does that apply to the question of whether or not foreign teachers are tarnishing the image?
Can teachers of color be effective educators? Absolutely. Should teachers of color be given preferential treatment? No. Are all teachers of color capable of giving good education? No. Are all whites? No. Should everyone care? Yes. Don't let the alias throw you off. I do give a damn about the students here. I don't give a damn about stupid forum names.