How to end intarsia knitting

I have the simple polka dot pattern from the Lion Brand website and I am a basic begginer knitter. I have read a ton about intarsia and watched videos and i get the concept. No where on the internet does it show or explain how to end. I have to make polka dots and when I get to the end, what do I do? Do I just knit the main color back in and snip the polka color? Will it undo itself? If someone could point me in the right direction, I would appreciate it.

You will have the main color on each side of each polka dot and you keep them both going until you have the entire polka dot done. Then you cut and leave a tail of the polka dot yarn and resume knitting with just the background yarn. Sooner or later (up to you) you will need to work in the ends hanging from the polka dot. If you find any loose place where you ended the dot try to work in the end so as to minimize it, then hide the rest of the tail, by working it into the back of the polka dot until it is nice and secure and then cut it off.

If there are any tails of background color work them into the background color and deal with them the same way as the others.