Here is the list of the helmets in my knowledge. They are listed in 3 categories: drivers, promotional, plain.
I'll also put the colour of the plastic helmet ( not the decals livery ) and special notes. If You own or You know more please add to the list.

DRIVERS

J. ICKS - DARK BLUE
N. LAUDA - RED
C. REGAZZONI - WHITE
J. SCHECKTER - WHITE
J. MASS - WHITE
J. LAFITTE - DARK GREEN
J. HUNT - BLACK
C. REUTEMANN - DARK BLUE
J. CECCOTTO - WHITE
M. ANDRETTI - WHITE ( ESSEX )
M. ANDRETTI - SILVER ( JPS )
A. PROST - WHITE/BLUE/RED ( TAG ERA )

PROMOTIONALS:

CHAMPION - WHITE
TEAM MERCURY - BLACK
BELL HELMETS - BLACK
LEYLAND - MEDIUM BLUE
JEB'S HELMETS - WHITE

PLAIN:

CHROME
RED - FORMULA 1 LOGO (TAG ERA)
MEDIUM GREEN - FORMULA 1 LOGO (TAG ERA)

Some Drivers helmets have different decals depending on sponsorship changes or model-year.
There are also some non Heuer helmets, but identical. I know one made by Meister Anker (red, no livery) and one made by Addex ( white, promotional for Bayer Enduro)

Have fun!