User blog comment:Miskos3/Fairy Tail Episode 253: Tartaros arc: Silver Memories, Review/@comment-186.45.128.222-20151003142718/@comment-4829046-20151003181312

@2nd anon I'd normally agree with you since the original appeal of the FT anime was the vibrant colour, but let's face it, it takes more time to adjust everything(contrast, tones and all that other stuff) and thus less attention to details like backgrounds and stuff(which were a major criticism in the first anime btw).

As Misk said, this fits the Arc's theme. It isn't a colourful thing. There is violence and death involved and the magic is more grim than it is pretty. The sunset effect that current episodes use is also a nice touch and I'm waiting to see if the progression of time is utilized properly and we get the dark tone that is shown in the OP.

The way I see it, paler colours = grittier mood and tone, while vibrant colours = peppy and upbeat mood and tone. Sure, plenty of gritty anime use vibrant colours, but almost all of them resort to the lighting effects the current episodes are using and this works great for thematic moments and isn't too hard on the budget.