Years	Decal	Shell	Mask	Stripes L to R	Stripe Width
?-1950-?	none	white	none	green	1/2"
?-1960	none?	green	gray	white	1/2"
1961-?	white player's #	green	gray/ white	white	1/2"
?-1965-1966-?	white spartan head - ala USC	green	gray/ white	white	1/2"
?-1973-?	huge white spartan head w/ black ol	green	gray	white	1/2"
?-1975	huge white spartan head w/ black ol	green	green	white	1/2"
1976	white player's #	green	green	white/ green/ white/ green/ white	3/8"- 1/4"- 1/2"- 1/4"- 3/8"
1977	white spartan head - armored style	green	green	white/ green/ white/ green/ white	3/8"- 1/4"- 1/2"- 1/4"- 3/8"
1978-1982*	white spartan head - armored style	green	white	white/ green/ white/ green/ white	1/4"- 1/4"- 1/2"- 1/4"- 1/4"
1983-1994	white S on right side only	green	white	white	1/2"
1995-1998*	white spartan head - armored style	green	white	white/ green/ white/ green/ white	1/4"- 1/4"- 1/2"- 1/4"- 1/4"
1999-2000	white spartan head - armored style	metallic green	white	white/ green/ white/ green/ white	1/4"- 1/4"- 1/2"- 1/4"- 1/4"
2001-current	white block "S", both sides	metallic green	white	white	1/2"

Notes:
*  - Same helmet design
^ - This mini helmet is an errant version. The S decal is of the wrong font, see RR (2) for the corrected version.
# - This mini helmet is an errant version. The outer white stripes are missing, see RR (2) for the corrected version.

Michigan St. 1950	Michigan State 1961	Michigan State 1965	Michigan St. 1975
Michigan St. 1976	Michigan St. 1977	Michigan St. 1990	Michigan St. 1997
Michigan St. 1999	Michigan St. 2001