Hello Jonathon, you are correct about the blushing in most cases.
However some only express the red cheek coloring as juveniles. Some Gold Marble Blushing (Koi or Sun Burst Angels) do not show the red cheeks as adults, we have some.
Black Blushers do not express it either because the black skin pigmentation hides it, but genetically they still have the blushing gene, same for blue blushers.
The blushing or stripeless gene as it is known here, makes interesting study for its ability to modify the looks of different fish in different ways, especially when cross bred in single and double dose of the stripeless.
Pete