Multi string with multi color

public Spanned setSpanColor(String string, int color){
    SpannableStringBuilder builder = new SpannableStringBuilder();
    SpannableString ss = new SpannableString(string);
    ss.setSpan(new ForegroundColorSpan(color), 0, string.length(), 0);
    builder.append(ss);
    return ss;
}

String a = getString(R.string.string1);
String b = getString(R.string.string2);

Spanned color1 = setSpanColor(a,Color.CYAN);
Spanned color2 = setSpanColor(b,Color.RED);
Spanned mixedColor = TextUtils.concat(color1, " ", color2);
// Now we use `mixedColor`