As stated in the title, I want to like this as it's got some superior aspects to it. The setting is pretty cool, and there's plenty of mileage that the author can get out of via discrimination, not only with the titular eye color, but also racial.
Too bad the MC is just awful. And I don't mean a bad person, but rather to the reader he's just a complete and utter bore. The girls are great, both the main cast (who are descended from the heroes, and clearly designed to be the harem) but also the older sister demon/devoted maid/etc character. Again, too bad because of the MC being so boring and uninspired! Because for whatever asinine reason the author came up with, the MC is also a shota, which personally creeps me out. Otherwise, the fact that he actually sleeps with the demon maid would be great! A protagonist who actually does something with his harem? How novel!
Except he's bland and emotionless. This might be one of those things where it's better in the source material (WN or LN, not sure) but here the fact that we get to watch this boring dude just lie there as a hot onee-san does stuff to him, and he just looks bored and uninvolved, REALLY lessens the appeal. I know it normally is applied to women, but he's the very image of a dead fish.
Hot onee-san+ dead fish shota. ..... suddenly i'm not impressed.
So yeah, the story is tolerable, the art is nice (but again, that's almost a BAD thing here, as it shows stuff I don't want to see!), the harem is pretty standard (you know, there's a tsundere, there's a coodere, etc - it's all pretty unimaginative, but that's not necessarily a bad thing... people like those girl archetypes for a reason), the action is ok, and so on.
There's a lot to like. If it weren't for the boring cardboard emotionless dead fish shota protagonist. Damnit author, why must you do this? This is why we can't have nice things.