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 | 46 | 27 | 11 | 8 | 96 | 48 | 48 | 92 |
| P | Wrexham | 46 | 26 | 10 | 10 | 89 | 52 | 37 | 88 |
| P | Mansfield TownMansfield | 46 | 24 | 14 | 8 | 90 | 47 | 43 | 86 |
| 4 | MK Dons | 46 | 23 | 9 | 14 | 83 | 68 | 15 | 78 |
| 5 | Doncaster RoversDoncaster | 46 | 21 | 8 | 17 | 73 | 68 | 5 | 71 |
| 6 | Crewe AlexandraCrewe | 46 | 19 | 14 | 13 | 69 | 65 | 4 | 71 |
| 7 | Crawley TownCrawley | 46 | 21 | 7 | 18 | 73 | 67 | 6 | 70 |
| 8 | BarrowBarrow | 46 | 18 | 15 | 13 | 62 | 56 | 6 | 69 |
| 9 | Bradford CityBradford | 46 | 19 | 12 | 15 | 61 | 59 | 2 | 69 |
| 10 | AFC Wimbledon | 46 | 17 | 14 | 15 | 64 | 51 | 13 | 65 |
| 11 | Walsall | 46 | 18 | 11 | 17 | 69 | 73 | -4 | 65 |
| 12 | Gillingham | 46 | 18 | 10 | 18 | 46 | 57 | -11 | 64 |
| 13 | Harrogate TownHarrogate | 46 | 17 | 12 | 17 | 60 | 69 | -9 | 63 |
| 14 | Notts County | 46 | 18 | 7 | 21 | 89 | 86 | 3 | 61 |
| 15 | Morecambe | 46 | 17 | 10 | 19 | 67 | 81 | -14 | 58 |
| 16 | Tranmere RoversTranmere | 46 | 17 | 6 | 23 | 67 | 70 | -3 | 57 |
| 17 | Accrington StanleyAccrington | 46 | 16 | 9 | 21 | 63 | 71 | -8 | 57 |
| 18 | Newport CountyNewport | 46 | 16 | 7 | 23 | 62 | 76 | -14 | 55 |
| 19 | Swindon TownSwindon | 46 | 14 | 12 | 20 | 77 | 83 | -6 | 54 |
| 20 | Salford City | 46 | 13 | 12 | 21 | 66 | 82 | -16 | 51 |
| 21 | Grimsby Town | 46 | 11 | 16 | 19 | 57 | 74 | -17 | 49 |
| 22 | Colchester UnitedColchester | 46 | 11 | 12 | 23 | 59 | 80 | -21 | 45 |
| R | Sutton UnitedSutton | 46 | 9 | 15 | 22 | 59 | 84 | -25 | 42 |
| R | Forest Green RoversForest Green | 46 | 11 | 9 | 26 | 44 | 78 | -34 | 42 |
| > League Two Full Table | |||||||||
