The desaturation of Halo

So it's been eleven years since Halo: Combat Evolved was released and in that time the Halo series has developed a lot. One thing that has changed a fair bit is the use of colour. As shown in the image below the armour colour of the protagonist, Master Chief, has become less and less saturated over time. The same can be said for numerous aspects of the game and it would seem that desaturated, gritty visuals have been becoming more and more popular over the years.