Why are there green and purple lines and some parts are black and whit

Those lines suggest either graphics driver corruption or failing graphics hardware. Firstly go to either your computer or graphics card manufacturer's website to download and install the drivers.

If that does not fix it, it could be a graphics hardware problem.

If it’s isolated to the internal LCD, it’s usually a TAB failure and a new screen is required. If you do not see this on an external display, the issue is with the internal LCD.

In the case of the Switch 3, it looks like you’re dealing with a touchscreen where the LCD is fused to the glass with LOCA glue. Sadly with these, the only good option is to scrap the assembly. It CAN be done while preserving the original, but I’m still playing with methods as I go when I get junk displays as I go. My first attempt was a success in the sense I broke no glass, but I broke internal components of the assembly. My second run is going better, but I broke the glass. As you can tell, you stand no chance as a DIYer if I’m having a hard time.