Thank you for that useless and off-point history lesson.
The issue is not whether brown is appropriate for suiting. It's that amongst summer-appropriate cloth, fresco is really second only to tropical wool in formality and a warm weather proxy for regular worsted suitings, so browns and tans are better left to linens and cottons. Afterall, regardless of history and specific contexts, brown and tan today are firmly and broadly known as more casual colors. To argue otherwise is akin to arguing that double-breasted suits are more casual than single-breasted for similarly accurate but ultimately irrelevant historical reasons.
In short, brown is fine for suitings, but brown suitings are more casual suitings. Hence, more casual types of cloth are more appropriate for brown suitings.
What about tan/cream wool flannels? Do you believe those are inherently incongruent? (I have no agenda - genuinely curious if you believe the same applies to woolen flannels)
Edited by francoamerican - 2/20/14 at 1:28pm