Today was looking for a Game Boy North America Time line.  Was unable to find a usable one so i started to go over what i could find here is what i have composed.  let me know if this is not correct or you have more data to support the time line.

Game Boy  July 21, 1989

Game Boy "Play It Loud"  March 20, 1995
    Vibrant yellow
    radiant red
    gorgeous green
    deep black
    "high-tech" transparent.

Game Boy Pocket (MGB-001)   

    Silver September 3, 1996
    Blue September 3, 1996

Game Boy Pocket (MGB-001)

    Red April 28, 1997
    Green April 28, 1997
    Yellow April 28, 1997
    Black April 28, 1997
    Transparent April 28, 1997

Game Boy Color (CGB-001)
    Grape Purple  October 21, 1998
    Atomic Purple  October 21, 1998

Game Boy Color (CGB-001)
    Dandelion Yellow    1999
    Berry Pink    1999
    Kiwi Green    1999
    Teal    1999