echo "<li><a href='".'http://gaming.webstro.eu/viewpage.php?page_id=3'."' alt='' style="color: yellow;">".'Pravidla'."</a></li>\n";

echo "<li><a href='".'http://gaming.webstro.eu/viewpage.php?page_id=3'."' alt='' style="color: #000000;">".'Pravidla'."</a></li>\n";

echo "<li><a href='".'http://gaming.webstro.eu/viewpage.php?page_id=3'."' alt='' class="barva">".'Pravidla'."</a></li>\n";

.barva {
  color: #000000;
}