A Darryn Stamp volley, a penalty from Terry Hawkridge and a late Dominic Knowles effort were enough to defeat the struggling Welsh outfit, for whom veteran Frank Sinclair hit the net in the first half.
Trinity opened the scoring after just seven minutes when a delicious cross from the right by Dominic Roma was met by a crisp Knowles volley which cannoned off the bar, before falling to a grateful Stamp who rifled into the net.
A period of confident passing followed for Trinity but they failed to build on their opener and paid the price 10 minutes before the interval.
Forty-year old FA Cup winner Sinclair was given far too much space inside the box and he gleefully smashed the ball into the top corner.
After seeing Colwyn take the initiative heading into half-time, it was the award of a spot-kick that saw the Blues regain the lead.
A cross into the box appeared to strike the arm of opposing skipper Danny Meadowcroft and the referee had no doubts about giving the spot-kick.
Hawkridge, believed to be the main target of watching Football League scouts within the crowd, confidently placed the penalty into the bottom-left corner.
Knowles then polished off proceedings with a tame shot which somehow trickled into the net.
Another boost for Trinity is that goalkeeper Jason White, who has been out for eight weeks, has revealed he is back in training with a view to returning to action over the coming month.
Trinity: Budtz 6, Young 5, Roma 7, Waterfall 7, Hone 6, Leary 6, D’Laryea 6, Hawkridge 8, Knowles 7 (Barraclough 79), Stamp 7 (Connor 57 5), Nelthorpe 7 (Yates 66 7). Not used: Wilde, Williams.
Colwyn Bay: Sanna 6, Richardson 6, Lea 6, Meadowcroft 5, Sinclair 6, Breeze 6 (Evans 71), Newby 6, Williams 7, Hopley 6, Darkwah 5 (Rainford 68), Holden 6. Not used: Taylor, Lloyd, Dunn.
Referee: Guy Stretton. Assistants: Robert Townsend and Declan Bourne.
Goalscorers: Stamp 7, Hawkridge pen 54, Knowles 77; Sinclair 35.
Bookings: Meadowcroft 53, Lea 84.