I have purple marks on my MacBook Pro screen

Hate to say it, Benek03, but it looks like it might be a screen problem. To make sure it's not a software issue, you'd have to boot up in safe (single user) mode, otherwise you'd have to book an appointment at your local Genius Bar and take it in. How to boot up in safe (single user) mode can be found on apple's support page for notebooks. You should also be able to run the Apple hardware test by holding down the "D" key on restart.

sorry I can't help you more

jb