Masked Lovebirds
Masked lovebirds are one of the "eyering" species.
Below is a picture of a green Masked - the natural, or "wild"
coloring.
Notice the wide, white ring around the eye. The
head should have a solid black "hood" over it, with yellow around the
neck, and a red beak. The flights are black.
A Blue Masked will have the eyering and black
hood, but a blue body with white around the neck, and a pink
beak.
I don't own any blue masked birds, but below (on
the right) is a dilute masked, which is very similar. The diferences
being that the dilute has more white on the head and body and white
flights.
(The bird on the left is a wild-colored Fischer,
and not as small as he appears. It is just the camera
angle.)