Alter Color module fieldset within theme settings form I've set up Color module for my theme - it works pretty well, but takes too much vertical space (I have a bunch of colors).
What i'm trying to do is to alter system-theme-settings form to make Color scheme fieldset collapsible.
So here's my code:

function test_form_system_theme_settings_alter(&amp;$form, &amp;$form_state) {
  drupal_set_message('DEBUG: ' . print_r($form['logo'], 1));
  // Above line prints array of logo settings - so function works well

  drupal_set_message('DEBUG: ' . print_r($form['color'], 1));
  /* This line prints nothing and I get:
   * 'Notice: Undefined index: color in test_form_system_theme_settings_alter()
   * (line 16 of /var/www/sites/all/themes/test/theme-settings.php).'
   */
}


As you can see, i can't alter $form['color'] because it doesn't exist.
Here's the color_form_system_theme_settings_alter function.

Am i missing something?
Definitly system-theme-settings is a core form where color module adding its fields using hook_form_alter in the same manner you are doing.

The point at which your hook_form_alter is invoked seems to be earlier then the color module's.

Check out hook_module_implements_alter to alter the registry of modules implementing a hook.