158867 was liveried in the Prototype Wales and West Livery around late 1999 to early 2000 i do believe it was, its livery was: Grey, Orange, Light and Dark Blue with Orange doors. Later 158745 and 158746 which transferred from Scotrail to Wales and West then received the Wales and West Alphaline Silver with Blue and Yellow livery.
The ex Anglia class 150s:
150213, 150217, 150227, 150229, 150231, 150235, 150237, 150255 & 150257 were transferred from "One" to "Central Trains" in exchange for 156402, 156407, 156409, 156412, 156416, 156417, 156418, 156419 & 156422.
Also at the same time as 150245 was transferred from Norwich Crown Point to Cardiff Canton along with 153311 & 153326.
The ex 'one' Class 150s were sent to ATW, but they were almost immediately then sent to FGW, at the time they were transferred to FGW they had been painted in to ATW livery but that was it. They didn't stay long with FGW though as they were taken for refurbishment, with 2+2 rather than 2+3 seating fitted, with ex Valley Lines 150s replacing them at FGW.
Yes that was back in 2008 as i remember travelling on 150213 from Newton Abbot to Gunnislake and back and it had its 3+2 seating with Regional Railways grey seat covers, and also i travelled on 150229 from Penzance to Teignmouth which was the same, once they got returned to ATW the original valley lines 150s appeared, 150278, 150279, 150281 i think it was?