Metter of fect, it’s oll dahrk.
Many would already know this but just in case, the “dark” side of the Moon is a mistaken reference to the portion of the Moon that faces away from the earth at all times, as the Moon is locked into an orbit where it rotates once every month (where month is given its more precise meaning, the period required for the moon to orbit around the earth). That period is 29.53 days (heliocentric perspective). Just about half of the Moon’s surface is never visible from earth. We had no idea what it looked like until the space age, and it is somewhat less dominated by lunar maria.
Both sides of the Moon get equal amounts of sunlight and darkness, as one could guess from the phases of the moon that we see on “our” side. At new moon, an observer a little closer to the Sun and in a direct line from earth to the Sun would see a full moon and a fully illuminated earth. They might even see a dark spot on the earth’s cloud systems if there was a total eclipse of the Sun underway.