The strange thing about the Praetorian and Mordian regiments is that they don’t look like other Imperial Guardsmen at all. Rather than wear the drab colors and camo patterns- inspired largely uniforms from both world wars and Rambo films, the Praetorians and Mordians wear dress uniforms to battle, with bright colors boldly displayed.
But despite the Grim Dark future being so populated with bright oranges and reds, it seems a little odd to paint the World War II inspired tank designs of the imperial guard that way. It is sometimes hard to imagine Imperial Guard vehicles in flashy coloring.
Of course, when they’re painted, Guard vehicles look really good in the bright colors.