Wtf is this

It was going so good until they started including slaves and calling darker skinned people barbaric. And then her trying to tell the auction guy that the dude that was covered up was merchandise wtf

This is actually a subversion of that? Slavery was common in that time period and, if you paid attention, a lot of the slaves for sale were fine-skinned, too. Social status seems to be a bigger indicator of slavery, with 'exotic' or desirable features being heavily favored. Pretty run of the mill stuff.

Her outing the guy and calling him merchandise? I mean, I'll give her a pass since she was trying to stop him from legit murdering a child and starting a war. Was it wrong? Yeah, people shouldn't do that in the real world.

The Kaluta are a tribe outside the empire that gives them trouble. Ofc any people outside the empire are going to be treated like barbarians, that's just simple human psychology (in groups vs outgroups). They just have a different culture that the empire doesn't understand because it goes against their own common sense. Nothing groundbreaking here.

Ya can argue this section is unneeded and yeah, for now I'd agree with that assessment. But nothing here seems to scream racism at me? The tribe, thus far, seems cool and the sister is a riot in how fun she is as a character. I'm intrigued in knowing more about them.

This right here. It could be excluded sure, but so far imo it's not handled badly. If author was racist, they would have made them plain villains with no character and personality.
So far it seems they don't plan to make them into that archtype. I also love the sister so much. The way she humbled the blonde prince was such a refreshing sight.
She was obviously saying all that she said in the knowledge, that the man was responsible for the young prince's death in the past and wanted to prevent it, and used words that would agitate him to make him slip up and back off.

Also yeah. Historically people called any culture they couldn't agree with or understand barbaric.
My ancestors had to abandon their original belief cos surrounding countries were christians and demanded we become that too or they would crush us. They called our original belief heretic and us barbaric and uncultured. We were originally nomadic, and traveled through eurasia and probably a bit further down south too, then settled in Europe. And then yeah...we got bullied into changing to christianity which is just sad. But proves that if author wants to portray the reaction of different cultures clashing in an age where the people didnt care to learn eachother's culture then imo its a realistic way they portrayed them.

There you guys go again bring up “oh this is historically accurate” bs be so fvcking fr bro. But whatever makes you guys feel better ig