PHP/MapScript: How to change the color of a point?

[Alexandre Abramides]

This is what I do to draw a point:

  $point = ms_newPointObj();
  $point->setXY($x,$y);
  $line = ms_newLineObj();
  $line->add($point);
  $feature = ms_newShapeObj(0);
  $feature->set("text"," ");
  $feature->add($line);
  $layer = $map->getLayerByName($layer_name);
  $layer->addFeature($feature);

What I need is to change the color of the point (RGB) according to some
condition, can anyone help me?

Alexandre.