void keyPressed()
{
  switch(key)
  {
    case '1':
      gnTimeStart = millis();
      gnColorMode = 1;
      break;
    
    case '2':
      gnTimeStart = millis();
      gnColorMode = 2;
      break;
      
      case '3':
      gnTimeStart = millis();
      gnColorMode = 3;
      break;
      
      case '4':
      gnTimeStart = millis();
      gnColorMode = 4;
      break;
      
    default:
      break;
  }
}