I thought it was common knowledge, but G-CLXC (according to G-INFO) was "chartered" and not Flybe owned. Most likely for AOC or to satisfy other license approval requirements. With a slim possibility it could be used for currency for certain post-holders, albeit unlikely.
With the relaunch of Flybe v.2 imminent, I would suspect favourable leasing deals have been struck with lessors that have Q400s already in Flybe purple colours sat on the ground. That'll certainly save a bit of money than getting new airframes or repainting others. Plus v2 gets to pick which are the newest, best maintained airframes with the least amount of cycles until next checks..