Is it paint and not vinyl then? I was sure the whole thing was one set of vinyl (well long bits stuck together), with the FCC specific stuff (name and the city lights bit) stuck on top again (thus making it possible to remove the branding later on).
As a result, whatever is on the side of the train is merely whatever was printed out. Thus, FCC has made the decision to change the design.
(Actually, I think the 377s were painted in purple weren't they - but I still think the 321s are vinyl).
First Groups newer liveries are a mixture of paint & vinyl...
As in the case of FCC & FGW - on most units, the bodysides are rubbed down, any repairs carried out if required, then repainted into First Groups Blue before the addition of whichever vinyl necessary - Local Lines, Dynamic Lines or City Lights...
In most cases the vinyls will already come in several pre-printed large panels -take the Mk3 Based unit - the middle sections vinyl panels will come in as little as 4 panels, to which the vinyl supplier will usually fit - usually companies like 3M...In the case of the 165/166 fleet, they were not repainted - just rubbed down and re-vinyled and repainted where necessary - ie front panel, window frames etc...
321 / 377 / HST Fleets - Full rubdown & repaint, with a simpler smaller vinyl section placed on the bodyside instead - Perhaps it's First Groups more Intercity-er type livery?
Something else has also come to my attention recently on several forums about FGWs 150127 appearing in plain blue & rubine red - Im in no doubt that it will be reliveried like all other Local Lines / West Of England 150s - Because, so far only 150121 & 127 have had a partial refreshes, and to re to someones comments about the local lines vinyls not in production anymore - Why? All it is is a vinyl, to which the artwork can be stored on a computer anytime and reprinted when required - FCC's City Lights livery is still printed for the 313s, so why should the Local Lines vinyls be any different!
We might be living in a Sticky Back Plastic / Blue Peter style railway these days, but at least the vinyls are cheap & easy to replace in case of vandal attack etc & provide a fairly quick way of any FOC & TOC to spread their brand across there respective fleets in a cheap, quick and cost effective way
So theres abit of my knowledge for you - if you want to read up on it or see some, the railway magazine were following some teams from 3M i think in a couple of issues ago - As part of FCC's 319 refurbishment at Wolverton Works.