In the MCU when we see the Kree they have blue skin and blue blood, such as Yon Rogg's team and Ronan the Accuser.
However when we see Yon Rogg and Mar Vell they don't have blue skin but rather more human colored skin and while this is the same with Carol she was actually human and only has blue blood because it was Yon Rogg's blood infused into her.
So what species is Mar Vell and Yon Rogg? if they are Kree is there a reason why they don't have blue skin like most all other Kree?
As shown in my answer aqui. In the comic universe, some Kree interbred with other species and created a Kree that looked like a Caucasian human.
The Kree were an evolutionarily stagnant race. This was due to a single member of the Kree race attempting to gain control of The Crystal of Ultimate Vision. This unnamed Kree found the crystal, but attempted to use it to become akin to a god, with powers as of those of the Phoenix Force. As punishment, the crystal "genetically froze their evolution in place" allowing the rest of creation to pass them by. In an attempt to further their development, some Kree bred with other species, producing the 'pink-skinned' Kree, who are similar in appearance to Caucasian humans. These pinks (also called 'whites') eventually outnumbered the blue-skin Kree, but were far from accepted amongst their brethren; many pink kree were exiled from the homeworld and put into forced labor camps on barren moons by their blue skinned cousins due to prejudice & racism. The Kree value what they consider to be their genetic purity, to such an extent that reproduction outside of the species is a strict taboo. In the Kree empire, it is a crime for a male non-Kree to impregnate any Kree.