How to change the color depending on a value in php

I would like the color circle to change in my program according to time

1 = Green
2 = Yellow
3 = Red

I share my code:

 <div class="ContenedorIndicador">

  <input type="text" name="Codigo" id="Codigo" placeholder="Codigo" required>
  <button type="submit" class="btn btn-success btn-sm" name="Iniciar" id="Iniciar">
    <span>Iniciar</span>
  </button>
  <button class="btn btn-danger btn-sm" name="Finalizar" id="Finalizar">
    <span>Finalizar</span>
  </button>

</div>

<div class="Contenedor1">
  <div class="table-responsive">
    <div class="panel panel-default">
      <div class="panel-heading">
        <h4>Viajes:</h4>
      </div>
      <table class="table table-fixed">
        <thead>
          <tr>
            <th class="col-sm-1">Fecha</th>
            <th class="col-sm-1">Codigo</th>
            <th class="col-sm-1">Status</th>
            <th class="col-sm-1">Cuenta</th>
            <th class="col-sm-1">Transportista</th>
            <th class="col-sm-1">ECO</th>
            <th class="col-sm-1">Placas Unidad</th>
            <th class="col-sm-2">Operador</th>
            <th class="col-sm-2">Numero T/R/M</th>
            <th class="col-sm-1"></th>
          </tr>
        </thead>
        <tbody>

          <?php while($row = $resultado->fetch_array(MYSQLI_ASSOC)){ ?>

            <td class="col-xs-1"><?php echo $row['fechaPrincipal']; ?></td>
            <td class="col-xs-1"><?php echo $row['comprobantePrincipal']; ?></td>
            <td class="col-xs-1"><img id="miImagen" src="images/CGris.png"></td>
            <td class="col-xs-1"><?php echo $row['clientePrincipal']; ?></td>
            <td class="col-xs-1"><?php echo $row['transPrincipal']; ?></td>
            <td class="col-xs-1"><?php echo $row['ecoPrincipal']; ?></td>
            <td class="col-xs-1"><?php echo $row['placasPrincipal']; ?></td>
            <td class="col-xs-2"><?php echo $row['operadorPrincipal']; ?></td>
            <td class="col-xs-2"><?php echo $row['numeroPrincipal']; ?></td>
            <td class="col-xs-1">
              <?php $var = $row['comprobantePrincipal'] ?>
              <a href="Bitacora.php?Ryder=<?php
                echo $row['comprobantePrincipal'];?>"
                class="btn btn-danger btn-sm">
                <span class="glyphicon glyphicon-list-alt"></span>
              </a>
              <a target="_blank"
                href="ReportePDF.php?Ryder=<?php
                  echo urlencode( $row['comprobantePrincipal']); ?>"
                class="btn btn-info btn-sm"
                name="accionPDF" id="accionPDF" title="Generar Reporte">
                <span class="glyphicon glyphicon-paste"></span>
              </a>
            </td>
          </tr>
        <?php } ?>
      </tbody>
    </table>
  </div>
</div>
</div>

</form>

</div>

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