A Gemara in Bava Batra 84a teaches:
For the sun is red in the morning and in the evening. And this is what we do not see it as red the entire day is because of our sight, which is not clear enough to perceive it.
Commentary of the Rashbam:
The brightness of the day is blinding and prevents us from discerning the sun’s true colour. It is only in the morning and in the evening when the sun is not so bright, that we can see its true colour.
The Gemara continues and discusses why the sun reddens in the morning and in the evening:
The sun reddens in the morning because it is then passing through the rose arbor of Gan Eden (Paradise). And it reddens in the evening, when it is in the west, because it is then passing through the opening of Gehinnom, which is in the west. And there are those who say the opposite: The redness of the morning sun derives from its rays being reflected off the fires of Gehinnom opposite it in the west; and the redness of the evening sun derives from its rays being reflected off the roses of Gan Eden opposite it in the east.
The redness of the morning sun can be attributed to its rays filtering through the red roses of Gan Eden.