Color may not match even on the real thing. Sometimes there can be changes in color in each paint batch even from the same paint source.
During this time period:
TTG: Overnight train, with sleepers.
Daylight: Day train, no sleepers.
Also, look at the color of the winged ball. If the ball is orange (the sun), it is a day train. If the ball is gray (the moon), it is an overnight train.