A red peg means that a color is in the right spot.
A gray peg means that a color is in the combination, but not in right spot.
No peg means that a color is not in the combination.
So below, two of the colors are in the right spot, one of the colors is in the combination but in the wrong spot, and one is not in the combination at all.
Thanks for playing MasterMind!
The answer was
Are you up for a greater challenge? Try WordMind, MasterMind with words!