The Marvel Cinematic Universe has showcased multiple alien species and how they interact with one another to create peace, war and everything in between. This has been best showcased with the Kree Empire and how they've made enemies with planets like Xandar and nearly eradicated species like the Skrull. However, with their focus on perfection and superiority, it's a surprise that, as a species, they're anything but.
Captain Marvel showed the audience the Kree homeworld of Hala and revealed that while Kree has been showcased as blue in movies like Guardians of the Galaxy, not all of them were. In fact, some had other skin colors that proved a level of diversity within their ranks. That said, the reason for this has led to an unspoken tension among the Kree Empire that perfectly captured the hypocrisy of their vendetta against species like the Skrulls.
Kree Subspecies Created Great Tension
In Marvel Comics, the Kree Empire traveled to many planets as they expanded their empire and met many new species. This, as expected, led to many Kree having children with the species they visited and creating Kree subspecies. Characters like Mar-Vell were known as "pink skins" and were treated as lesser forms of Kree by the original blue-skinned Kree. While this wasn't shown in Captain Marvel, it's likely that this was still practiced, at least to some degree.
The Kree Empire has existed for millions of years, and while the prejudices that were introduced may have died down to the point that both subspecies of Kree could coexist, that prejudice may still exist on some level. Mar-Vell and Yon-Rogg represent some of the best minds and warriors on Hala and are treated with respect, even though they aren't pure-blood Kree. But even though the hate surrounding their version of Kree may still exist in some circles, that same hate has fueled Kree to take their prejudice to new planets.
Kree Prejudice Encapsulates Their War on the Skrulls
The Kree/Skrull War has defined both species for generations, and while shows like Secret Invasion have shown that not all Skrulls are benevolent, the Skrull Empire was still a victim of hate. The Kree continued to plan their galactic takeover, which led to the near eradication of the Skrulls and the destruction of their homeworld. But rather than this war being started over something logical, it was started because the Kree hate anything that isn't them, something that they can't handle even among themselves.
Their hate for those that aren't pure-blood Kree may have dissipated over the millennia, but it's never disappeared. Instead, it was transformed and pushed to a new face, the Skrulls, and now the Kree Empire has proven that they never learned from their past. Now, the Skrulls have become victims of a mindset fostered by a species that had nothing to do with them because the Kree, originally, couldn't accept diversity in their race.