SpannableString strTitle = new SpannableString("病情描述（必填项，请至少填写20个字）");
strTitle.setSpan(new ForegroundColorSpan(getResources().getColor(R.color.pre_text_gray_999)),4,19, Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
diseaseDescribeTitle.setText(strTitle);
原文：http://www.cnblogs.com/xgjblog/p/4511802.html