Here are the tilenames used by the commands on the server:

$tiles{0} = "air";
$tiles{1} = "rock";
$tiles{2} = "grass";
$tiles{3} = "dirt";
$tiles{4} = "stone";
$tiles{5} = "wood";
$tiles{6} = "shrub";
$tiles{7} = "blackrock";
$tiles{8} = "water";
$tiles{9} = "waterstill";
$tiles{10} = "lava";
$tiles{11} = "lavastill";
$tiles{12} = "sand";
$tiles{13} = "gravel";
$tiles{14} = "gold";
$tiles{15} = "iron";
$tiles{16} = "coal";
$tiles{17} = "trunk";
$tiles{18} = "leaf";
$tiles{19} = "sponge";
$tiles{20} = "glass";
$tiles{21} = "red";
$tiles{22} = "orange";
$tiles{23} = "yellow";
$tiles{24} = "lightgreen";
$tiles{25} = "green";
$tiles{26} = "aquagreen";
$tiles{27} = "cyan";
$tiles{28} = "blue";
$tiles{29} = "purple";
$tiles{30} = "indigo";
$tiles{31} = "violet";
$tiles{32} = "magenta";
$tiles{33} = "pink";
$tiles{34} = "darkgrey";
$tiles{35} = "lightgrey";
$tiles{36} = "white";
$tiles{37} = "yellowflower";
$tiles{38} = "redflower";
$tiles{39} = "mushroom";
$tiles{40} = "redmushroom";
$tiles{41} = "solidgold";