Place each egg, cut-side down, into a muffin cup paper liner.
Spoon mayonnaise into a plastic resealable bag; snip 1 of the bottom corners of the bag. Pipe mayonnaise through the opening around the base of each egg half.
Portion red food coloring into a small bowl, blue food coloring into a second small bowl, and black food coloring into a third small bowl. Dip a clean and sterile small-tip paintbrush into the red food coloring and paint small lines onto each egg to represent 'veins', making sure to get a little of the red food coloring into the mayonnaise.
Rinse brush and make a blue circle on the top middle of each egg to represent the 'iris'. Rinse brush and paint a black ring around the iris and put a dot of black in the middle of the iris for the 'pupil'.