Curious about the changes you can make with the light and wanting to test things somewhere where you can actually see what happens as reality changes, you decide to head home, figuring that you can use the light on your family. At least you know that changing them back will be easy enough if things get too strange.
Ideally testing it on campus would have been better, or at least less weird, but with you being a commuter student because of how close the college is to your house, and classes not starting for another few days you don't really want to wait. Besides, even if you were to head to the campus there won't be too many students there yet, just a few early arrivals and you don't yet know which, if any of them will be in your classes, so you won't get the chance to observe the changes the way you will with your family.
On the bus ride there you can't help but mess with the flashlight a little more when a guy in his early teens gets on at the next stop and immediately sit down across from an attractive couple in their mid-twenties and stare openly at the woman. She is dressed in a rather short skirt and a fairly low cut blouse, so you can understand his staring, still, you decide to have some fun.
Since the teenager is so interested in the woman's breasts you decide to do something for him. Switching the light to 'or' and turning it to a mid-pink setting you shine it on the boy's chest.
The changes are difficult to notice beneath his loose fitting grey t-shirt, but when he leans back in his seat slightly you can see the twin mounds of his budding breasts pushing against the fabric. They're smaller than you expected, but you realize that it's probably because he's young and has some growing left to do. When he finishes getting through puberty he'll likely have quite impressive cleavage, but you want something that's more immediately visible so decide to turn the light up a bit more.
His breasts expand farther, reaching a decent looking b-cup, resting rather heavily beneath his clothing since he's not wearing a bra to support them. Gingerly he reaches up and adjusts his shirt over his breasts, nipples hard with arousal poking against the fabric. Glancing nervously from side to side to see if anyone's watching, he rubs at his chest, fingers circling slowly around his nipples as his face starts to grow flushed.
So far so good you decide, before switching the light to a low blue setting and shining it on his crotch. The bulge that had been previously visible there shrinking slightly as the relevant anatomy is reduced. Because of how baggy his pants are, it's hard to say how small he is now, but it's more likely than not that even when he gets through puberty there's no way he's going to have much luck with the ladies with what he has, not that it matters thanks to what you have in mind.
For your next bit of fun you turn the slight to the 'sp' setting and turn the light up higher while keeping it blue. Immediately he begins paying as much attention to the muscular looking man as he is to the woman, but it won't be that way for long. You turn the light to pink and lower the intensity and watch as his interest in the woman diminishes. From the way you have the light set you figure that he's most likely bisexual with a strong bias towards men, something that will be interesting for him as he gets older and his breasts continue to develop while his manhood remains small.
Then, because you can't help yourself, you adjust the light again, lowering the intensity of the blue setting to the minimum and flipping it back to 'or', except this time you don't aim it at the teenager. Instead you shine it on the woman he was looking at. You start with her hair, watching it recede back into a rather tomboyish cut, short, but not outright masculine. In the process you get her face and watch as her makeup disappears and her features become ever so slightly more angular.
The bus hits a bump, causing the light to dip a little lower, getting her chest and shoulders, her shirt no longer fitting quite so well as her breasts flatten to nearly nothing and her shoulders grow wider. Shifting position she adjusts her blouse now that there's nothing left for it to show off and bringing her arms and hands into the light. There the changes are slight, maybe her fingers get a little thicker and her arms get a little more muscular, but nothing really drastic.
Having already changed most of her upper body, you take the light lower, shining it down her left side and then her right, careful to get her stomach, but miss her crotch. Her hips narrow, her but and thighs going from curvy to skinny with maybe a little little muscle.
Just to finish things off you change her legs, watching as her legs put on a bit of muscle, but nothing too impressive.
The teenage boy you changed earlier goes back to watching her, clearly intrigued by her androgynous appearance.
Well, you decide, if he's that interested, you might as well have a little more fun.
You push the intensity of the light a little higher.
This time you start from bottom to top, starting with the woman's legs.
The muscle that's there becomes more toned, increasing slightly in mass so that her legs are fit looking, but still skinny. Higher up her thigs grow again, gaining muscle to partially replace her lost curves. Again you are careful to not shine the light on her crotch, wanting to make her a tomboy, not a full man. There are no further changes to her hips, and her blouse hides the changes to her stomach, but you're certain that she's become more toned there. Her arms, which are resting at her sides have certainly gained muscle, her fingers becoming visibly thicker as she reaches over to hold her boyfriend's, or maybe husband's, hand.
When you shine the light on her chest, watching her shoulders become broad and her chest muscular, her blouse has to change slightly to accommodate her new build. It fits slightly better now and shows off muscle rather than cleavage.
You decide against changing her face any further, fine with a boyish, slightly feminine head on an otherwise lean and athletic body, but you're not done yet.
To complete her tomboy look you turn the light to the 'in' setting and shine it across her chest. The changes to her clothing catch you off guard. Instead of her blouse turning to a t-shirt it turns into a near form-fitting tank-top to better show off her muscular chest and tones stomach, as though she's about to go out for a jog, or maybe is heading to the gym. What happens with her skirt only adds to that impression, becoming a pair of impressively tight shorts.
The thing is, now there's so little left to show that she's a girl, you simply have to make one last change.
Flipping the light to a low pink and returning it to the 'or' setting you shine it carefully across her chest, watching as softness develops there on top of, but not replacing the muscle, as she grows a pair of a-cup breasts, nowhere near the size of what she originally had, but still enough to give her a hint of femininity.
Satisfied, you turn the light off and put it away.