Bascially Bustr, it comes down to birds like these
Both these shots are of 345th FS, 350th FG Jugs in the MTO. Our old Airwarrior buddy, the late Earl Miller, flew Jugs with this bunch. The urgency of continued operations often meant the painting had to wait. Note that in this flight of 4 there are two veteran birds with the 345th yellow and blue checks on the nose and yellow lightning bolt on blue on the tail along with the squadron codes. Also note one of the new Jugs has the yellow checks and the yellow lightning bolt, but they haven't had time to put on the squadron codes or the blue checks or trim. And the 4th Jug has no markings added yet. But here they are lugging bombs on the way to a target.
That top picture is one of my all time favorites. Some serious formation in some tough looking birds.
Generally the USAAF birds were much more colorful the closer to the end of the war we got. More planes available and more pilots as well as time to paint.