I can’t find this ANYWHERE! My main menu is a dark gray. The “current page” is a slightly lighter gray. I’d like to disable this, so the menu does NOT indicate the current page at all. Where can I change this setting or color? Site in question: http://www.ianeric.com
That color is not not directly configurable (but it is generated based on the configured menu background color).
You can remove it with a bit of CSS:
#access ul > li.current_page_item,
#access ul > li.current-menu-item,
#access ul > li.current_page_ancestor,
#access ul > li.current-menu-ancestor {
background-color: transparent;
}