table.sched {
  align:center;
  bgcolor:lightslategray;
  width:80%;
  border:1;
  cellpadding:40px;
  cellspacing:20px;
  font-size: 1.3em;
  margin-bottom: 10px;
  font-family:Verdana;
}

table.sched tr {
  align:center;
  valign:middle;
  bgcolor:lightslategray;
}

/* Innenabstand für alle Zellen */
table.sched td {
  align:center;
  valign:middle;
  text-align: left;
  border: 1px solid orange;
}

.a {
  background-color: mediumvioletred;
  color: #ffff00;
}
.b {
  background-color: dimgray;
  color: #ffff00;
}
.c {
  background-color: slategray;
  color: #ffff00;
}
.d {
  background-color: lightslategray;
  color: #ffff00;
}
.e {
  background-color: #808080;
  color: #ffff00;
}
.f {
  background-color: #908080;
  color: #ffff00;
}
.g {
  background-color: #998080;
  color: #ffff00;
}