asian wives with other races

I'm wondering if others have found what I did, that my wife (Japanese), when she finally agreed to play, prefered that other men NOT be white-- since I was already white, I think she figured she'd "been there done that." She didn't want other asians or white but was OK with any other race.
It first came up with us because when she finally agreed and allowed me to LOOK for a partner, the first guy I hit it off with (online) was black. I wasn't sure how she'd feel, I asked her "what about interracial" and her answer was "we already are." Which of course was true- so I went on to explain to her that the guy was black. She's older (she was 48 at that time) and she had no clue that anything was different about blacks such as size or stamina; she said no problem (and then fell in love with the guy- but that's another story).
After him, she clearly told me she actually would prefer to try other races. She was with black, latin, Arab, Indian (and two whites, lucky guys).
One interesting thing- when I lived in Japan long ago, there was clearly a "racial hierarchy" among most. Whites were considered superior (because of our cultures and the west beating Japan in the war) and then other races were lower-- with latins and blacks at the bottom (sorry, no offense intended, but I clearly heard that from older Japanese more than once). And at one point my wife said something like "it's better for US if the men I do are not white, so then they (other race men) won't be as much competition to you." She clearly referrred to non-sexual sides of them, because sexually most WERE bigger than me (some quite big). So I am wondering if other white husbands or asians heard similar ideas from their asian wives?