The old South West Trains fleet is kind on an anomaly when it comes to an operator livery because unlike other TOCs, their trains are colour-coded depending on the type of service they provide in contrast to other operators such as CrossCountry, Greater Anglia and Great Western Railway who also operate with regional and express passenger trains but with a uniform livery. ScotRail does a similar thing with it's HST's in their own branded intercity livery contrasting with the otherwise stopping and regional saltire liveried units. So it's kind of hard to argue their case for meeting a criteria of distinctive and striking when it's dependent on the type of service provided. The Class 444 livery was very much identical to the old East Midlands Trains livery, although that said they are both still distinctive of Stagecoach as a wider brand even if their brand isn't included in the operator name.
Which makes SWR’s fleet look much tider, especially when one of each class is coupled.
Design unity across the fleet might be a benefit for South Western Railway as a brand, but I disagree on their livery looking tidier. The old striped patterns on the side with varying shades of white and blue are not aesthetically pleasing to look at, and it definitely has the issue of obnoxious overbranding with the logo on the end of each coach along with the company name beneath the windows on every coach.
Well, I think the question is asking more why do you like that livery.
I think the best way I can simplify the intent of the thread is that it's more a discussion as to what makes a good livery from both a customer and business point of view which is why I talk about things such as being pleasing to look at along with distinctive designs that help signify the brand of the operator rather than just what people like. As an example, I like the Transport for Wales livery, but on the FLIRT units it doesn't look very distinctive and wouldn't look out of place on the Swiss railway network. The two subjects are of course likely to be correlated of course, and it would be foolish of me to think otherwise, but I'm hoping that we can also largely look beyond our own personal preferences.