SpannableString spannableString = new SpannableString(matchResult);

int index = matchResult.indexOf(mKeyword);

if (index != -1) {

    spannableString.setSpan(new ForegroundColorSpan(ContextCompat.getColor(holder.itemView.getContext(), R.color.search_txt_green)), index, index + mKeyword.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);

}

itemView.setText(spannableString);