Years	Decal	Shell	Mask	Stripes L to R	Stripe Width
?-1975-1976	white "NU"	purple	white	none
1977	white "NU"	purple	white	white/ purple/ white	3/8"?- 1/2"- 3/8"?
1978	purple "NU"	white	purple	purple	1/2"
1979	purple "N" - script letters	white	purple	purple	1/2"
1980	purple "Cats" - script letters	white	purple	purple	1/2"
1981	white "N"	purple	white	none
1982-1990	white "N" w/ silver ol	purple	white	none
1991-1992	white "N" w/ silver ol	purple	purple	none
1993	white "N"	purple	purple	none
1994-current	white "N"	purple	black	none

Northwestern 1975-76	Northwestern 1975-76	Northwestern 1978	Northwestern 1979
Northwestern 1980	Northwestern 1981	Northwestern 1982-90	Northwestern 1991-92
Northwestern 1993	Northwestern 1997