Hi, I'm Gerry Pepper from germany. English is a pretty hard language to write in, 
so go easy on me with the spelling and punktuation ;)

While I'm sure the other verions of the song found here at UG are excellent, they 
seem to not suit my stile of playing.
I thought this could be the case for some of you as well, so here is my chords based vesion.
I tune down 2 steps (to D flat) but it's singable in standart as well.
Have fun!

(Parts between |: and :| are repeated)

Chords:
Am: X02210
G:  32003X (Mind the alternative G Chord)
C:  X32010
F:  133211
Em: 022000

To get the melodie in with the chords, I play:

    Am      G     C       F     Am    G     C       F...usw
e|----------------------0-1-0---------------------0-1|
h|--------1-3---0-1---1-------3-1---1-3---0-1---1----|...
g|------2-----0-----0-------------2-----0-----0------|
D|----2----------------------------------------------|...
A|--0-------------3-------------0-----------3--------|
E|----------3-------------1-----------3-------------1|...

Listen to the song to get the rythm down.

Am        G           C
Yo listen up here's a story
 F             Am       G          C          F
About a little guy that lives in a blue world
        Am          G              C        F
And all day and all night and everything he sees
        Am
Is just blue
     G   C          F 
Like him inside and outside
Am       G            C           F 
Blue his house with a blue little window
      Am      G
And a blue Corvette
         C        F        Am
And everything is blue for him
       G             C     F
And himself and everybody around
               Am    G       C      F 
Cause he ain't got nobody to listen to

Chorus:
      Am         G         C  
|:I'm Blue da ba dee da ba daa
      F         Am        G         C 
da ba dee da ba daa da ba dee da ba daa 
      F         Am        G         C
da ba dee da ba daa da ba dee da ba daa 
      F         Am        G         C
da ba dee da ba daa da ba dee da ba daa:|

Em
I have a blue house with a blue window 
Em                               Am
Blue is the colour of all that I wear 
Em
Blue are the streets and all the trees are too 
G                       Am
I have a girlfriend and she is so blue 
Em
Blue are the people here that walk around 
Em                                       Am
Blue like my Corvette, thats standing outside 
Em
Blue are the words I say and what I think 
G                          C
Blue are the feelings that live inside me

Repeat Chorus

C          F
Inside and outside
Am       G            C           F
Blue his house with a blue little window 
      Am      G
And a blue Corvette 
         C        F        Am         G
And everything is blue for him and himself 
         C    F
And everybody around 
               Am    G       C      F
Cause he ain't got nobody to listen to

Feel free to correct me if you find mistakes, I'm also allways thankfull for feedback.
Have fun playing!