Why did they paint the 300Tdi blue?

Good morning guys and i hope you are all safe and well.

I have seen some military 300Tdi engines painted duck egg blue colour and was wondering why and is there any benefit to painting the engine this colour?

I like the look of it and would like to know more on why they did this?

Cheers Landy Lee

Suggestion here that it denotes reconditioned items, no idea if it's right.
MOD Recon Blue Green. Traditionally a classic colour used by the MOD, this colour is rated to 170 degrees centigrade. Used to paint all reconditioned engines, gearboxes and other mechanical items. This shade has also been colour matched against new mechanical items, still boxed in original packing from Land Rover and authenticated by a professional restorer. MOD Recon Engine Blue Green is also known as Recon Engine Green,Ex Army Recon Engine Blue, Duck Egg Green, Duck Egg Blue, Ex Army Engine Paint amongst others.
https://paintman.co.uk/shop/mod-recon-blue-green/