<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512">
  <circle cx="256" cy="256" r="250" fill="#607D8B"/>
  <text x="256" y="310" font-family="Arial" font-size="160" font-weight="bold" fill="white" text-anchor="middle">SM</text>
</svg>