What areRed/Green/Gray/Blue Shirts?

This explains the 4 categories of recruits what don't immediately count against the 85 commit limit. I didn't know there is such as thing as blue shirts! From USA Today Sports yesterday

Twenty-five prospective student-athletes signed with Ohio State's football
program last February, part of a recruiting class ranked by most major
services as one of the best in college football.

Of this group, just four saw action during the Buckeyes' 2015 regular
season. The rest of the signing class participated in every team activity,
from practice through film study, but did not play in a single game,
maintaining a season of eligibility while acclimating themselves to their
new surroundings.

It's a process known as redshirting, and it's the most common tool used by
coaches and programs to prepare student-athletes unfamiliar with a far
higher level of competition.

Some incoming recruits are simply too good to redshirt: Alabama wide
receiver Calvin Ridley and defensive back Minkah Fitzpatrick played crucial
roles in the Crimson Tide's most recent national championship, for example.
Some new arrivals avoid a redshirt season out of necessity, to fill a void
on the roster.

Though recruiting breeds superlatives - the best class, best player, best
positional group - it also overbuilds expectations. Ridley, for example, is
the exception. Most incoming recruits escape notice, spending their first
seasons on campus not as irreplaceable contributors but in developmental
roles.

Those prospects who officially join Football Bowl Subdivision programs on
national signing day can be split into two distinct groups: those who will
play from the start and those who won't. You can separate this group further
by the color of their shirts.

There are redshirts, greenshirts, grayshirts and blueshirts. Each term is
used to define an incoming student-athlete's eligibility status, as well as
how an individual program views a prospect's ability to contribute in the
immediate and long term.

Players who redshirt are able to participate in every team function minus
the games themselves; a player who plays in a single game will lose his
redshirt status. By taking a redshirt, players are given five years to
complete their four seasons of on-field eligibility.

There are exceptions, as in the case of injury. Should a player suffer a
season-ending injury before certain criteria are met - before the start of
the second half of the season and before he competes in three games, for
example - he can petition for a medical hardship waiver, which is awarded by
the NCAA.

Former Virginia Tech defensive tackle Luther Maddy, a likely mid-round pick
in this year's NFL draft, was given an additional year of eligibility after
missing all but four games of the 2014 season because of a knee injury.

Greenshirt recruits are those who enroll one semester ahead of schedule and
join an FBS program for the start of the spring term in January. Typically,
greenshirts are the most likely to earn immediate playing time as a true
freshman.

There are two reasons for this. For starters, the ability to enroll early
places greenshirt recruits ahead of the curve, giving them time to acclimate
to campus, participate in spring practice, to fully digest an offensive or
defensive scheme and the opportunity to develop in a team's strength and
conditioning program. Greenshirts are also very often among the nation's
best prospects at their respective positions, eyeballed far in advance by
FBS programs as recruits capable of making an immediate impact as true
freshmen.

Greenshirts in this year's recruiting cycle include Georgia quarterback
Jacob Eason, Ohio State defensive end Jonathon Cooper, Auburn wide receiver
Kyle Davis and Alabama offensive tackle Jonah Williams.

Grayshirts are recruits who are offered a delayed scholarship. Essentially,
grayshirts will postpone their enrollment until after the conclusion of the
upcoming season; they will take classes, often as part-time students, but
not officially join the program until the ensuing spring semester.

Schools use the grayshirt to add recruits without sacrificing scholarship
numbers. Though a grayshirt graduates at the same time as other prospects,
delaying the player's enrollment allows a program to count that scholarship
offer toward the following season's total - making the grayshirt a helpful
tool for those programs who tend to over-sign recruits.

Arizona will add four grayshirts to their official roster this spring. All
four - defensive back Antonio Parks, tight end Jamie Nunley and offensive
linemen Keenan Walker and Harper Sherman - signed national letters of intent
with the Wildcats last winter but delayed their official enrollment until
January.

Meanwhile, blueshirts represent the newest loophole for FBS programs to
accumulate depth while not affecting their annual numbers. Like grayshirt
recruits, blueshirts are counted toward the next season's scholarship total.

There is one distinct difference, however. Unlike grayshirts, a blueshirt is
able to enroll and participate in team events in the fall. This allows
programs to get the best of both worlds: FBS schools can delay a scholarship
for the following year, allowing them to over-sign beyond the 25-scholarship
limit, and get the use of a prospect immediately rather than waiting until
the following spring.

The use of a blueshirt was first popularized by New Mexico State, which
would support its numbers by enrolling prospects right after the beginning
of the fall semester and then place them on scholarship. Tennessee has also
embraced the use of blueshirts under coach Butch Jones.

Go Blue!!