In short, yes. The key is can those two specific blue parakeets get along. Color doesn't matter, but the two parakeets personalities may clash. If you have had a parakeet for a long time, he may not take kindly to an intruder. Often if you have three, two will bond and pick on the outsider. It is really about the individual birds not the color.
Depending on your Parakeets color, it's perfectly normal for parakeets to not have blue on it's head...
no
There have been cases where they do, but it is not recommended to mix different species of birds in the same cage. Cockatiels are much bigger than parakeets, and can cause serious damage from a single bite.
yes
Bluebirds, Blue Jays, and certain Parrots, and Parakeets can be blue.
Yes
blue and white or green and yellow
Slow, short, and peaceful introductions are needed. Some parakeets will just never get along however, and should be housed separately.
There are many, more than 120 species and sub-species, The most common in homes are: Blue, Green, and Rare Parakeets.
that's normal
its multi colored
If a parakeet's beak is blue, it's a boy. If it's red/pinkish, It's a girl!