<p>
  <span id="y">Y</span>
  <span id="o">O</span>
  <span id="u">U</span
</p>

@import url('https://fonts.googleapis.com/css?family=Ubuntu');

p {
  margin: 40px auto;
  font-family: 'Ubuntu', sans-serif;
  font-size: 100px;
  font-weight: bold;
  color: #dfdfdf;
  text-align: center;
}

#y {
  text-shadow: 0 1px 2px #75b663,
      1px 3px 1px #5ea04b, 
      2px 5px 1px #5b9c49, 
      4px 7px 1px #518b41, 
      6px 9px 1px #477939,
      8px 11px 1px #3d6831,
      10px 13px 1px #335729,
      12px 15px 1px #294521,
      14px 17px 1px #1e3418;
}

#o {
  text-shadow: 0 1px 2px #9d64c4,
      1px 3px 1px #9759c0, 
      2px 5px 1px #8b46b9, 
      4px 7px 1px #7d3fa6, 
      6px 9px 1px #6f3894,
      8px 11px 1px #613181,
      10px 13px 1px #532a6f,
      12px 15px 1px #45235c,
      14px 17px 1px #381c4a;
}

#u {
  text-shadow: 0 1px 2px #c48564,
      1px 3px 1px #c07d59, 
      2px 5px 1px #b96e46, 
      4px 7px 1px #a6633f, 
      6px 9px 1px #945838,
      8px 11px 1px #814d31,
      10px 13px 1px #6f422a,
      12px 15px 1px #5c3723,
      14px 17px 1px #4a2c1c;
}