Personal experience with satsumas (a tiny orange only available in FL from late December to around early February), local lemons and even store-bought lemons tells me the same: brown's OK. Even slightly dried-out's OK.

The satsumas, which once ripe are extraordinarily sweet and juicy, get slightly dry at the brownish/shriveling stage but are just as good and sweet. Lemons get juicier, like running down your hand and arm juicy.

Limes, on the other hand (at least store bought) are a no-go at any stage past ripe. They get dry and shrivel and are as hard as rocks. You might dull a knife just trying to cut through one.

I've never had Sumos.