Why not cut out a piece dry wall to cover and patch the hole it is easy enough and you can place your mount - the end result will be that it looks right, not like someone had a can in the ceiling and then placed a track light over the hole.
They might sell you scraps of dry wall at your hardware store - ask you might be surprised that they have them - sometimes some break apart in handling. (Although a big board is about $15.00 ).
In the ceiling you can be a bit sneaky, run a small screw through the center of your circular piece of dry wall - use a stir stick with a hole in the center for your screw to go into. Place the stir stick above in the ceiling and then run the the screw from the drywall piece into it - it will hold it in place for you and your repair.
Although for me in this case I like to run a board from joist to joist so it is more secure and you can drill or cut the opening you want for the track light.
This way you can run your 3 wires directly to the track light.. and all will be well.
As for texture or popcorn or not - paint does change color over time. The paint will probably be a satin or matte finish, matching the color can be done by taking a small sample from around the can hole (big enough for a machine to read the color.). Practice first then do, especially if it is a textured ceiling. I find the can is best for knockdown textures, the popcorn I would do manually for that small of an area - dabbing the brush in the paint and then into my popcorn and then dabbing on the ceiling the tip of the brush - straight against the ceiling (holding brush with handle inline floor to ceiling) and dab around - no specific pattern.
BTW: They do make hanging track lights:
Amazon dot com Search in Tools & Home Improvement : Hanging track light.
see additional edit about painting. But I think the search at A will provide you a simpler fix - if you can find a style you like.