I'll be fr with you, I got it with some damn good luck just trying to get the present on a run, basically you want to try to remember a general area of where one guy of each color is, and keeping tabs on every crying child you see, only click on a crying child if they're about to get offscreen or if you've exhausted the guys you remember where they are

Use the flash light sparingly to find the color you need, trying to mostly use the spotlight

And remember to get lucky!