Here What I Found 
Why do boy babies get dressed in blue,
and girls in pink?
Long ago, many people believed that evil spirits hung around the
nursery, but that these spirits
were repelled by certain colours. The most potent colour was blue,
associated with the heavenly sky.
Blue was believed to frighten away demons and rob them of their
power. So blue on a baby was not
only adornment, but also seen as a very necessary precaution.
Now this was a long time ago, when girls were considered inferior,
so boys got the really
potent blue colourit didn't matter what colour girls got. The
assumption is that later generations chose
pink for girls to symbolize that new rosy all-over-pink
look
