I've cut them thinking I only needed to cut away excess. But now the setup colors (the red green and blue colors) don't match up with any of the left or right options when setting up. The Neo box works well, but looks like I'll have to get new strips. Unless if there's a way to work around it (my TV is a 75 inch) is there a way to purchase just the strips?

were you able to make it work with 3 pin connectors?
Hi if the light strips were cut mistakenly then they can connect together by do some welding, which is high demanding that we strongly discourage you from doing it. And it's not recommended to buy other light strips as those ones might not be compatible with Lytmi ones.
Hello! There's a lot of videos on YouTube how to connect cutted led.
Also you can contact Lytmi support via email to buy new led strip.