The 19-year-old, who was recently with eighth-tier side Bedford Town, had been on trial at the Essex club in recent weeks.
The youngster signs a one-year contract at the club, after featuring in three Colchester Under-21s fixtures last month.
Barnes is eligible to feature for Colchester against Northampton Town on Tuesday.
Restore Data
| Team | P | W | D | L | F | A | GD | PTS | |
| C | Stockport CountyStockport | 44 | 26 | 11 | 7 | 91 | 44 | 47 | 89 |
| P | Mansfield TownMansfield | 44 | 23 | 13 | 8 | 87 | 45 | 42 | 82 |
| P | Wrexham | 44 | 24 | 10 | 10 | 84 | 51 | 33 | 82 |
| 4 | MK Dons | 44 | 22 | 8 | 14 | 74 | 61 | 13 | 74 |
| 5 | Crewe AlexandraCrewe | 44 | 19 | 13 | 12 | 68 | 61 | 7 | 70 |
| 6 | BarrowBarrow | 43 | 18 | 14 | 11 | 58 | 49 | 9 | 68 |
| 7 | Crawley TownCrawley | 44 | 20 | 6 | 18 | 69 | 65 | 4 | 66 |
| 8 | Walsall | 44 | 18 | 11 | 15 | 66 | 65 | 1 | 65 |
| 9 | Doncaster RoversDoncaster | 43 | 19 | 7 | 17 | 63 | 63 | 0 | 64 |
| 10 | Gillingham | 44 | 18 | 9 | 17 | 43 | 53 | -10 | 63 |
| 11 | AFC Wimbledon | 44 | 16 | 14 | 14 | 57 | 47 | 10 | 62 |
| 12 | Harrogate TownHarrogate | 44 | 17 | 11 | 16 | 55 | 62 | -7 | 62 |
| 13 | Bradford CityBradford | 43 | 16 | 12 | 15 | 52 | 55 | -3 | 60 |
| 14 | Notts County | 44 | 17 | 7 | 20 | 88 | 85 | 3 | 58 |
| 15 | Morecambe | 44 | 17 | 9 | 18 | 63 | 76 | -13 | 57 |
| 16 | Newport CountyNewport | 44 | 16 | 7 | 21 | 61 | 71 | -10 | 55 |
| 17 | Tranmere RoversTranmere | 44 | 16 | 6 | 22 | 63 | 64 | -1 | 54 |
| 18 | Accrington StanleyAccrington | 44 | 15 | 9 | 20 | 57 | 66 | -9 | 54 |
| 19 | Swindon TownSwindon | 44 | 14 | 11 | 19 | 74 | 78 | -4 | 53 |
| 20 | Salford City | 44 | 12 | 11 | 21 | 63 | 80 | -17 | 47 |
| 21 | Grimsby Town | 44 | 10 | 16 | 18 | 55 | 72 | -17 | 46 |
| 22 | Colchester UnitedColchester | 43 | 11 | 11 | 21 | 57 | 74 | -17 | 44 |
| 23 | Sutton UnitedSutton | 44 | 9 | 13 | 22 | 53 | 78 | -25 | 40 |
| R | Forest Green RoversForest Green | 44 | 9 | 9 | 26 | 41 | 77 | -36 | 36 |
| > League Two Full Table | |||||||||
