Good one Sergio. From what I've seen, the interior was a mix of Bronze Green, with green ZC, and Interior Green on fittings such as seat frames and brackets etc. Thequilted padding in various areas, such as the cockpit side walls, was a sage green colour, similar to a lightened version of RAF Cockpit Grey Green.
These pics are of the interior of the B-25C 'Grumpy', when it first arrived at Duxford in the late 1980's (now back in the USA in RAF markings), when it was in original interior finish, apart from 'modern' extra seats and instruments etc. Ignore the 'modern' fittings, and look closely at the various areas, and the differences can be seen.
Other photos, including period shots, show similar colours throughout the B-25 series.
Hope these help.