In the main comic continuity, Captain America has typically been depicted as a white character. However, there have been alternate storylines and versions where the role has been taken on by characters of different races.
Sure. In the comic universe, Isaiah Bradley has taken on the role of a black Captain America. This addition brought more diversity and new storylines to the Captain America mythos.
One idea could be that Captain Marvel and Black Widow are on a mission together to infiltrate a powerful and secretive organization. They have to rely on each other's unique skills, with Captain Marvel using her super strength and flight to get them in and out of tight spots, while Black Widow uses her espionage expertise to gather intel.
Sam Wilson's journey to becoming Black Captain America is quite a tale. Sam was a veteran who had a strong sense of justice. When he became Captain America, he was in a difficult position. The public's perception was a big hurdle. But he was determined. He trained hard to be worthy of the shield. His backstory as a man who had seen the hardships of war and fought for what was right gave him the moral compass needed for the role. He had to deal with super - villains as well as the public's changing view of what Captain America could be. His story shows how anyone, regardless of race, can step up and be a hero, carrying on a great legacy in a new and exciting way.