remove welcome to drupal 7

Error is apply with theme omega 4 with your subtheme.

In page_preprocess.inc insert line red color

function your_theme_preprocess_page(&$variables) {
  // You can use preprocess hooks to modify the variables before they are passed
  // to the theme function or template file.
  //  $is_front = $var['is_front'];
  if (drupal_is_front_page()) { $variables['title']=""; }
}