That was a sly one ...
Not so much that we should ignore yellowing as that it is not something to get het up about. Choose the best that are available, by all means, and clean them of surface grime and the like, but also accept the inevitability of imperfection in a flawed structural material.
How sensible, in hindsight, was the black livery of the Performa 5400DE and PPC 5500. Or even this alternative.
de