I've been able to piece together some information on draft prospects the Colts have expressed interest in. These are players the Colts have either interviewed, worked out, scouted (attended Pro Days or work outs), or discussed favorably at the NFL Combine. I've placed the sources above to the names:
New Era Scouting:
Justin Beaver, RB, Wisconsin-Whitewater
Mackenzy Bernadeau, G, Bentley College
Alley Broussard, RB, Missouri Southern
Titus Brown, DE, Mississippi State
Curtis Cutts, S, Central Michigan
Jeremy Geathers, DE, UNLV
John Greco, OT, Toledo
Joey Haynos, TE, Maryland
Marcus Howard, DE/LB, Georgia
Tyrell Johnson, S, Arkansas State
Danny Lansanah, LB, Connecticut
Jona Lee, MLB, Charleston Southern
Blake Mitchell, QB, South Carolina
Jalen Parmele, RB, Toledo
Jack Williams, CB, Kent State
Justin Beaver, RB, Wisconsin-Whitewater
Mackenzy Bernadeau, G, Bentley College
Alley Broussard, RB, Missouri Southern
Titus Brown, DE, Mississippi State
Curtis Cutts, S, Central Michigan
Jeremy Geathers, DE, UNLV
John Greco, OT, Toledo
Joey Haynos, TE, Maryland
Marcus Howard, DE/LB, Georgia
Tyrell Johnson, S, Arkansas State
Danny Lansanah, LB, Connecticut
Jona Lee, MLB, Charleston Southern
Blake Mitchell, QB, South Carolina
Jalen Parmele, RB, Toledo
Jack Williams, CB, Kent State
KFFL:
Joey Haynos, TE, Maryland
Jolonn Dunbar, LB, Boston College
Luke Swan, WR, Wisconsin
Jon Banks, LB, Iowa State
Curtis Johnson, LB/DE, Clark Atlanta
Michael Peterson, TE, Northwest Missouri State
Andy Studebaker, LB, Wheaton College
Dan Davis, DT, U Conn.
Coltpower (Note: This is from their front page, not from subscriber info)
Brad Cottam, TE, Tennessee
Herald-Dispatch:
Bernard Morris, QB, Marshall
Doug Legursky, C, Marshall