private CharSequence relativeSizeSpan(CharSequence source, int pos) {
    final SpannableString ss = new SpannableString(source);
    if (viewPager.getCurrentItem() != pos) {
        ss.setSpan(new ForegroundColorSpan(0xffa8a5a5), 0, source.length(), 0);
    }
    else {
        ss.setSpan(new ForegroundColorSpan(0xff787777), 0, source.length(), 0);
    }
    return ss;
}