Colors begin military work. Q telling vets to BE READY…For God and Country… the President can now deploy whatever forces he wants instead of the Marines, but in practice that simply doesn't happen, except for small actions by small, covert SOCOM teams, and stuff like that. Whenever it is determined that an actual military task force needs to put boots on the ground somewhere (in country possibly?)and establish an American military presence, the Marines are still the go-to. This is especially true in “flash-points” around the globe, when unstable situations develop quickly and without much warning.
Oorah is a battle cry common in the United States Marine Corps since the mid-20th century. It is comparable to hooah in the US Army and hooyah in the US Navy and US Coast Guard. It is most commonly used to respond to a verbal greeting or as an expression of enthusiasm
https://www.tecom.marines.mil/News/News-Article-Display/Article/528540/colors-ceremony-more-than-pomp-circumstance/